Enabled sceneDB v2 and associated db upgrade (removes columns: bounded, continent, region and adds: created, last_modified) and modified associated classes accordingly + Scenes class: added ContentValues constructor, toContentValues(), formatData() + Added partial downgrade support to DB + Catch SQLite exceptions while DB upgrade or downgrade
renamed engine package to (more appropriate) core
Added scenes activity rendering sample 3D cube using jPCT as rendrer