suppress warnings when compiling assimp with ndk

Signed-off-by: Wayne Wolf <wayne.ron.wu@googlemail>
fix egl no context issue after resume from thumbnail

the Program object will be deleted when the Render
init routine called twice on the same Render object.
Fix this issue by deleting Program object beforehand
at the right time.

Another change is move setRenderState call in AppContext
to appropriate event handler to avoid race in the mainLoop.
A good solution is to combine render loop to the android
looper interface.

Signed-off-by: Wayne Wolf <wayne.ron.wu@googlemail>
change how app calls dzy

Signed-off-by: Wayne Wolf <wayne.ron.wu@googlemail>
change namings

Signed-off-by: Wayne Wolf <wayne.ron.wu@googlemail>
Move all mesh data to a single continuous memory area

in order to use Buffer Object per mesh

Signed-off-by: Wayne Wolf <wayne.ron.wu@googlemail>