User login + submission up/down votes complete

Submission up/down votes implemented using custom view with custom
drawable states.
Still need to work on dynamic layouts for logged in/logged out view.
Merge branch 'allen'
Merge branch 'Danny'
Some merge bugs fixed

- a layout file I was working on wasn’t committed
- subreddit list back button handled correctly
User login/logout + drawer menu layout change

Drawer menu consists of an expandable list view + a list view.
When the second list view (possibly list of subreddits) is expanded
beyond the vertical space of the drawer, we may need to enclose both
lists in a scrollview and handle touches manually. (using onTouch)
displaying submissions in a subreddit chosen