Merge branch 'release/1.2.9'

Merge pull request ether#1433 from ether/release/1.2.7

Release 1.2.7

Merge branch 'release/releases-1.2.6'

Merge branch 'master' of github.com:ether/etherpad-lite

Merge branch 'master' of github.com:ether/etherpad-lite

Merge pull request ether#1311 from ether/release/releases-1.2.3

Release 1.2.3