Action bar spiner instead of progress dialog; fix infinate loading;

Use the activities progress functionality to set a spinner in the action bar instead of a progress dialog
Keep count of the number of Start and Finished messages received to know when loading is finished.
 As these messages could come in any order and at any time, use an AtomicInteger to ensure thread safety.
 This should ensure that after data is finished being fetched, the loading spinner will disappear.
GerritURL: Add ability to construct project list request URLs; new string comparison method
Change visibility of menu items out of overflow

Change-Id: Iea0dcb11683b99bafd66f06212bdacc4649bd754