remove unnecessary casts and tests for null, discovered using NetBeans (#1285)
* remove unnecessary tests for null, discovered using NetBeans
* jme3-core: remove unnecessary casts
* jme3-examples: remove unnecessary casts
* jme3-vr: remove unnecessary casts
* jme-plugins: remove unnecessary casts
* jme3-terrain: remove unnecessary casts
* jme3-desktop: remove unnecessary casts
* jme3-android: remove unnecessary casts
* remove unnecessary casts, discovered using NetBeans
* TerrainQuad: back out one casting delta that's not a removal
* TerrainPatch: simplify generateLodEntropies() after removal of the cast
* TerrainPatch: simplify reIndexGeometry() after removal of the cast