Update readme
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 ubuntu-14.04
Merge remote-tracking branch 'origin/ubuntu-14.04' into fedora-20
Merge remote-tracking branch 'origin/arch'