Error log is too verbose

Error log is really too verbose, resulting in hundreds of messages being written per second and flooding the error log, also causing IO spikes.

For example let's take this error where maxscale reaches max connections, it will log an error for each connection error, in my humble opinion the rate of error write should be limited.

2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Splitter Service: Refresh rate limit exceeded for load of users' table.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Splitter Service: Refresh rate limit exceeded for load of users' table.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Splitter Service: Refresh rate limit exceeded for load of users' table.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Splitter Service: Refresh rate limit exceeded for load of users' table.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Invalid authentication message from backend. Error : 42000, Msg : User 'prddun' has exceeded the 'max_user_connections' resource (current value: 1000)
2016-07-26 04:42:28 error : Splitter Service: Refresh rate limit exceeded for load of users' table.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.
2016-07-26 04:42:28 error : Backend server didn't accept authentication for user prddun.