MDEV-3882: .deb versions lower than upstream repo, causing install failure

The official Debian Wheezy MySQL packages have versions like 5.5.30+dfsg-xxx.
Such version is larger than 5.5.30-yyy, so apt prefers it.
So use instead 5.5.30+maria-yyy, which is larger and can be pulled in
automatically by apt.

Also included are a couple of fixes for test failures in buildbot.

mysql-test/suite/innodb/t/innodb_bug51920.test

@@ -36,7 +36,7 @@ let $wait_condition =
 # depending on platform.
 #
 connection con1;
--- error 1317, 2006, 2013
+-- error 1317, 2006, 2013, ER_CONNECTION_KILLED
 reap;
 connection default;
 DROP TABLE bug51920;