Update README.md
Fix README.md
Add kernel 3.12.x to well supported list
Merge remote-tracking branch 'origin/ubuntu-12.04' into ubuntu-13.04
Merge remote-tracking branch 'origin/ubuntu-13.04' into ubuntu-13.10
Merge remote-tracking branch 'origin/ubuntu-13.10' into fedora-20
Merge remote-tracking branch 'origin/fedora-20'