Make mGerrit's presence clearer

I've heard repeatedly that people did not know this app
is included in all AOKP builds. This message is much clearer
to users about mGerrit's location.

Patch Set 2: missing backslash Thanks guys!
Patch Set 3: Correct grammar in summary

Change-Id: Ibaac55f49bacd0627a37766b20f85edcc172a328
DynamicChangelog

Github commit viewer that supports two modes
1) all commits since last update in chronological order *http://gerrit.sudoservers.com/#/c/4542/*
2) select package to view commits in project *api.github.com*
   (allows favorite packages selection)

**fast-forward port from jb branch**

PatchSet 2: rebase
PatchSet 3: use koush's image caching for gravatars
            organize classes
            remove duplicate projects (they only appeared
                afrer the screen was repopulated)
PatchSet 4: fix menu cycling
            fix backstack tracking
            remove unused vars
            code clean up

Change-Id: I7fabaf44562d02f251977a4a5a04ced252768b5e