Group selector for main page

Depends on I18ffdae4 of Translate

Change-Id: I994251e807304efcfea7d9fe95a251064984a3d3
Add translate and proofread actions shown on hover

Change-Id: I39e26cf4373662bab274c1ecba6a45c790adfd25
Merge changes I39e26cf4,I994251e8

* changes:
  Add translate and proofread actions shown on hover
  Group selector for main page