[Android] Sort the cores in the CoreSelection activity alphabetically. Also document the IconAdapter class, along with its IconAdapterItem interface.
[Android] Document a large amount of the Android front-end classes (also some methods).

Also adjusted the tab indentation of the GPL waiver method, was one tab too far.
Merge pull request #371 from lioncash/master

[Android] Sort the cores in the CoreSelection activity alphabetically.