Added link to coding guide wiki page
comments added/removed for MenuCommands
Merge pull request #1915 from feinstaub/minor_fixes

comments added/removed for MenuCommands
Selecting items in FormCommit improved, should update diff view only when needed
restore last selected items on reload

(cherry picked from commit 28ecafa4e995d195b7784f93078d13e6868b2e83)

Conflicts:
	GitUI/CommandsDialogs/FormCommit.cs