Merge pull request #1 from verdurin/master

Update README
Merge pull request #2 from verdurin/master

Add SL 6.4 support
 - Added RTEs for ARC.
 - Enabled CVMFS CMS site symlink.
Merge pull request #3 from verdurin/master

SL64 fixes
Merge pull request #4 from verdurin/master

Add missing SL64 kickstart
Add initial version of CMS Open Data node definition