Move Connectivity To Service

[timstableford]

The connectivity should be moved to a background service to allow notifications to be pushed when the app is not in the foreground.

[patrickjquinn]

I'm actually seeing a lot of warnings about dropped frames in the android debugger, suggesting that too much is done on the main thread (read: MainActivity.java), how much of this could be moved to background threads? (I cant believe that Android still doesn't give priority to GPU cycles at this stage in the game, its shocking).

[timstableford]

There are a number of long items done on the UI thread that could be moved. For now I've left them be because they don't have a notable performance impact. I'll take a look :)