Hi Jeff,
for the first conflict, it might be one of those introduced by a previous faulty upgrade. Could you please run
dpkg -l | grep -i maria
and
dpkg -l | grep -i mysql
and paste the output?
There are some steps to fix broken dependencies if you have them, depending on what you have, we'll see what needs to be done.
But even after that, you can't install the new libmariadbclient18 just yet, if you have mariadb-galera-server 5.5.32 (which you apparently do). Your system upgrade will work normally, but it will keep back libmariadbclient18 and libmysqlclient18 on the versions compatible with mariadb-galera-server until the new galera release is out.
Sure: (apologies - don't know the <pre> or <code>markup for this system)
ii libmariadbclient18 5.5.32+maria-1~wheezy amd64 MariaDB database client library
ii libmysqlclient18 5.5.32+maria-1~wheezy amd64 Virtual package to satisfy external depends
ii mariadb-client-5.5 5.5.32+maria-1~wheezy amd64 MariaDB database client binaries
ii mariadb-client-core-5.5 5.5.32+maria-1~wheezy amd64 MariaDB database core client binaries
ii mariadb-common 5.5.33a+maria-1~wheezy all MariaDB database common files (e.g. /etc/mysql/conf.d/mariadb.cnf)
ii mariadb-galera-server 5.5.32+maria-1~wheezy all MariaDB database server with Galera cluster
ii mariadb-galera-server-5.5 5.5.32+maria-1~wheezy amd64 MariaDB database server with Galera cluster binaries
ii mysql-common 5.5.33a+maria-1~wheezy all MariaDB database common files (e.g. /etc/mysql/my.cnf)
ii libmysqlclient18 5.5.32+maria-1~wheezy amd64 Virtual package to satisfy external depends
ii mariadb-common 5.5.33a+maria-1~wheezy all MariaDB database common files (e.g. /etc/mysql/conf.d/mariadb.cnf)
ii mysql-client 5.5.31+dfsg-0+wheezy1 all MySQL database client (metapackage depending on the latest version)
ii mysql-common 5.5.33a+maria-1~wheezy all MariaDB database common files (e.g. /etc/mysql/my.cnf)
>> apologies - don't know the <pre> or <code>markup for this system
Not your fault... There is no markup in the comments here 
So, from what I see, the packages that are expected to be upgraded got upgraded (mariadb-common and mysql-common). The rest is kept back due to the conflict between the client libraries and the current Galera server. It shouldn't anyhow affect your system. If it does, please let us know.
For the first conflict that you posted, my guess is that 5.5.33-rel31.1-566.wheezy comes from Percona repository – at least I can't figure what else it could be, Wheezy is still on MySQL 5.5.31 (and their packages are named X.Y.Z+dfsg etc.), and ours are named +maria. If you indeed have a Percona repo in your sources.list, you might have conflicts like that in the future. Probably you could use some tricks described in https://mariadb.com/kb/en/installing-mariadb-deb-files/#version-mismatch-between-mariadb-and-ubuntudebian-repositories – it was mainly created to deal with conflicts between MariaDB and MySQL, but it might apply to Percona as well.
But again, even if you resolve the conflict, currently an attempt to apt-get install the newest libmariadbclient18 will prompt for the Galera server removal: the packages can't be installed alongside, and since the user insists on installing the one, the system suggests to remove the other. When you just run apt-get upgrade, without specifying that you really want to install the library, the system skips upgrade of the library and all packages that depend on it, which is why your MariaDB client is still 5.5.32.
Hopefully, it won't be too long till the next version of MariaDB Galera server is out, then your packages will be up to date again.
Does it make sense? Please comment if it doesn't or if you have any further questions.
Fab - many thanks. We do indeed have a Percona repo in our sources. We will wait for the maria+galera build to upgrade the server as you suggest.
Hi Jeff,
mariadb-galera 5.5.33a has been released, did it solve the problem you were observing?
Closing as fixed since MariaDB-Galera 5.5.33a has been released, please comment if you still have issues installing it