Magic Cube

Remove the concept of a 'TwistyActivity' altogether.

Hide most of the TwistyActivity methods inside objectlib.

Simplifications

Move RubikControl to objectlib (as 'ObjectAutomator')
Hide ObjectPreRender inside objectlib and move its APi to ObjectControl.

Move ObjectControl, the next big chunk of code, to objectlib.

Move PreRender to objectlib.
This code is now shared betweeen the Rubik and Tutorial activities.

Move more code to objectlib.

Remove all files that have been separated into a new library 'objectlib'

Refactoring: split the 'objects' package into two, 'objects' and 'objectlib'.
The point: we're going to need to move the 'objectlib' stuff into its own library module, and that's because we're going to create a new app module which needs access to it.

1) add missing call to BlockController.onPause() / onResume() to the Tutorial activity
2) rearrange BlockController's error reporting to make the case where the MessageSender thread has died separate
3) in such case, resurrect the thread
4) simplify and harden the EffectMessageSender