Merge pull request #1 from aripringle/master

Make priorities plugin installation optional and add a couple of additional yumrepo parameters
Merge pull request #2 from aripringle/master

add a couple of repos with extrarepo support
Merge pull request #3 from aripringle/master

merge from upstream
Merge pull request #52 from diablomedia/master

some repo updates/additions, add ability to disable the priorities plugin
add mysql-community repos