Add --bind-address parameter for outgoing client connections

Client library has the MYSQL_OPT_BIND option for this already, so the feature only needs to be exposed via command line option handling.

MySQLs client binaries have this option since 5.6, and had it even earlier in the MySQL Cluster releases.

mysql-5.6.40 > bin/mysql --help | grep bind

  --bind-address=name IP address to bind to.

bind-address                      (No default value)

Background: when a client system has multiple interfaces / IP addresses, the OS kernel can pick whatever interface it prefers to connect to the server. Especially if multiple client IPs are in the same network, this usually means: pick the first one it has in the interface list.

I originally implemented the patch for this back when still working for MySQL AB, as back then my Laptop would always choose to do replication with my desktop over slow/shared WLAN, even when having a cable plugged in that connected it to the desktop directly, as the WLAN device was somehow always initialized first ...