Some unification done to simplify camera switching.

Some code refactoring done.

Rair hangs on library installation fixed.

made it to give more verbose errors when arguments of wrong types are passed, added setters with types (e.g. setInt, etc)

Frame format setter added to both views.

Old Android support added;
Android 4.1.x fixes added;
Thead sync added;
Camera errors handling added.

Nexus 7 support added.

OpenCV initialization moved to onResume event to support package installation waiting.