Comment 7 for bug 1668934

From #debian-openstack:

<georgelorch> jamespage, well, as you already know, PXC is based pn PS, which is based on MySQL, so PXC inherits all changed that occur along the chain. We do not have a stone cut policy on small features improvements within a minor series but generally anything significant must go into the next major series release. So no, minor updates are not limited to bugs only. New features and improvements might come in as well. Anything that might be a major difference like file format changes, deprecation or changing of option behaviors, etc... must only go into new major series releases.