Added some CRAZY hawtness to envsetup.sh

-bash completion for git command and remote+branch names
-branch of git repository in which working directory is rooted displayed on PS1
-added rst and rup helper scripts (rst <branch name> is repo start <branch name> <projects>, where projects is the project containing your working directory, unless otherwise specified

Change-Id: Ie9249998ff43ddebaa1d29128e0e5061759740a0

Conflicts:
	envsetup.sh
rst+rup -- find project root, then find repo root.

Change-Id: I166ae81170c5889a428399468034f49419aea4d8
Fix git branch on PS1.

Change-Id: I6a2ee113914bae7e73caa3142018a64488c30a68
nukehawtness: add cd to rst

If you're not in the directory, cd into it

Change-Id: I34f2eda21f6e0604e690a5288960d0dd4dca84ab
rst: when calling repo start, stash changes, and return to where the HEAD was when it was called

Change-Id: I77eda74bc51f0b504927cae1f1961b6f8721bdb5
don't try to stash when project(s) explicitly passed to rst

Change-Id: Ida111131ec7e4676e7566eae0308e0552446d7c1
rst: fix calling rst from directory inside a project's subdir

Change-Id: I75ad8913a5970537349d71785129caf7d60cb26c