pkgutil: add multiple-target support in latest_version

This fixes #5606.
Add versionadded directive to docstring

This adds a versionadded directive to the docstring for the new 'random'
keyword in cron states.
Add versionadded directive to docstring

This adds the versionadded directive to the docstring for the new "pkgs"
support added to pkg.purged/removed states.
pkgin: fix purge() function

This function needed to accept the "pkgs" argument and pass it through
to remove(). Without this change, pkg.purged states will traceback.
Merge pull request #5611 from terminalmage/quickfix

Use versionadded directive to denote new features
Merge pull request #5610 from terminalmage/issue5606

pkgutil: add multiple-target support in latest_version
Start on the 0.16.0 release notes
Add docs on prereq and prereq_in
Add multi master tutorial
Add pillar ref to the front page
kill the print