Added some threading

Each AsyncTask inherits from AbstractDataManagerTask. Every place in the
DataManager where we do stuff with the remote datastore, we need to
create a task that does that. Then instantiate, pass context, and call
.execute() on it to run it in a different thread.

Pretty much everything in DataManager will map to one of these tasks.
The AddQuestionTask is an example to follow. Other tasks may require
UI-thread updating to notify views of changes. These go in the thread's
onPostExecute() method.

Notice the carreful use of getting q[0] in the variadic (by interface)
function.
Merge pull request #145 from linster/master

Added threading to AddQuestion.
Add some ES VO classes from Victor
Instantiate dataStores outside of DataManager constructor
Add abilitly to fetch questions and answers from ES
Clean up some tests.
Add GetQuestionList implementation for RemoteDataStore.
Minor Changes. Later reverted.
Removed username stuff from DataManager

Now in ClientData only. Fixed bugs.
Actually fixed all user name stuff.
Moved all favorite stuff in ClientData

Ripped it out of data manager.
REFACTORED ReadLater into ClientData.

Ripped it out of DataManager. Fixed some lovely wtfs.
Fixing Tests.

Still have DataManagerTests to write.
GetQuestion sorta done

Changed it to a void. Callbacks should manually fetch the question they
need out of the thread.

Lots of breaking. Will fix.
GetAnswer is now complete in the DM.

Changed to return Void. Lots of breakage expected all throughout the
app. Will fix.
Sprinkled some comments about null callbacks

Null callbacks cause datamanager methods to act in UI blocking mode. We
can incrementally write callbacks in the rest of the app to gradually
get us into multithreading.
AddQuestionComment is now multi-threaded
GetQuestionComment now multithreaded.

When I added the Callback parameter, nothing broke. Someone needs to
make sure we are actually calling this in the app.
AddAnswerComment is now multithreaded
GetAnswerComment now multithreaded

Nothing broke when I changed the function signature. Need to make sure
it's actually being called.