Updates in the contributing doc, add context and detail.

overview/contributing.rst
-------------------------
  - Remove inative email addresses.
  - Added links and detail in Steps to successful PRs
  - Fixed a few document references that were literal or not resolving.
  - Update ONF contacts for topics.

Change-Id: Id01c982bb82604575536ab7a341bdc6a7cf9580d
diff --git a/VERSION b/VERSION
index 35a5840..e249ffa 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.11.1-dev2
+2.12.0-dev1