Added ActionBar Button to Actionbar (AddTask)

Change image to + rather than bars. Add dialog as a response to button
push. The code for responding to buttons should be placed in
onOptionsItemSelected. addTask() added, currently a stub.
Changed addTask to createTask

Naming convention changes
Merge remote-tracking branch 'origin/master' into EVEN-BETTER-UI-BRANCH
Stuff and things

The button adds tasks and stuff