Version bump to 2.1.0 and added Readme

1. Version bumped spec to 2.1.0.
2. I didn't know how to build a binary RPM for install so I looked it up and made some instructions for those who might not know offhand (READMEs are nice anyway).

If you accept the pull, I recommend you change line 15's git url to match your repo.

Cheers,
Chris