Adding hold and unhold functions to both aptpkg and yumpkg.  Adding initial support to be able to put packages on hold from states.
Adding a check in yumpkg to ensure that yum-plugin-versionlock is installed.  Adding versionadded to aptpkg, yumpkg and pkg.py for new features.
Merge pull request #11963 from garethgreenaway/develop

Additions to yumpkg.py, aptpkg.py and pkg.py