Fix selinux permissions for non-primary MariaDB/Galera nodes

Galera nodes started after the bootstrap node will use rsync (and
a few other cmds) to sync up with master; yet on Fedora 20 this
is causing a number of selinux AVC denials.

Fedora bug is https://bugzilla.redhat.com/show_bug.cgi?id=1145619

Change-Id: Ifb97b3f92fefdef1d57c87907292aeb4a27c3a49
Closes-bug: 1373150
Merge "Fix selinux permissions for non-primary MariaDB/Galera nodes"