Meta: automatic translation workflow state changes

This patch introduces typical state change rules for
translation message groups on Meta. To the best of
my understanding, these settings will have the 
following effects:

* When the first chunk is translated, move the group
  state to "Progress".
* When all chunks have been translated, move the 
  group state to "Proofreading".
* When all chunks have been reviewed, the group will 
  move to the "Ready" state.

See https://wikimedia.mingle.thoughtworks.com/projects/online_fundraiser/cards/1603

This change should be socialized within the Meta
translation community.  So far, I've gotten only
positive feedback in IRC (June 6) and on the Talk
page, https://meta.wikimedia.org/wiki/Meta_talk:Babylon#Automatic_translation_workflow_state_changes

Change-Id: I6873085219f92ca87e10d777d4e05f290c53a24d
Merge "Meta: automatic translation workflow state changes"