Refinement pass on editing summary panel.

Updates to canned edit summary choices and wording to sync
with Kenan/Vibha's list.

Used designer's color scheme for canned edit summary buttons.

Centralized WMF colors in single file - changed various places
to reference these colors.

Fixed annoying issues causing search keyboard to be hidden
unexpectedly.

Moved some things out of "Defines" file since they really
didn't need be outside of their respective view controllers
as they weren't referenced anywhere else.

Change-Id: Icc17003b1d167c295c3229bb53d2aadea8f6302e