Drop the short paragraph about branches.

Branches in git are very ephemeral and we don't
use them in any special or particular way.
diff --git a/ContributionReviews.wiki b/ContributionReviews.wiki
index 2c2d5c6..dc49525 100644
--- a/ContributionReviews.wiki
+++ b/ContributionReviews.wiki
@@ -190,10 +190,6 @@
 Patches from [ContributionReviews#Suggested_patches_from_casual_contributors casual contributors] will, by definition, need to be committed by someone other than the
 author but Mercurial repository history will indicate contributor as committer.
 
-=== Branches ===
-
-Previously branches were used for releases only, due to the unfriendly merge nature of svn we didn't use branches for "long term development". However since we switched to Mercurial repository we can now use branches more extensively.
-
 == Documentation ==
 
 Code files should include enough internal documentation in the form of `__doc__` strings, comments and functions with self-explanatory names (see PythonStyleGuide) that the automatic documentation suffices.  This is the recommended way to ensure that code documentation and the code itself stay in step.