Rotation, translation, parent model delivering mod

- rotate function moved to entity class
- mParent field removed form mesh - parent model will be sent only during draw
- additional rotation functionalities built_in in the entity class
- additional FPP object handle added
- additional skybox and ground objects added
missing mtl added
missing obj and mtl files added
another missing mtl's
missing obj added
Be aware of moving object. W + A + S + D + Space + backspace
first basic FPP movement implemented

- camera roation and controlled motion introduced
- uh60 model introduced
- Added getPosition and lookingAt functions to entity
blackhawk images added to assets
Camera motion methods expanded. FPP functionality.

- FPP functionality improved
- camera has its own rotation functions in mesh
- Entity can return its position, orientation and position
Merge branch 'master' of https://github.com/sabus/OpenGlExamples
Merge branch 'translation_rotation_scaling_simplifications'
Merge branch 'master' of https://github.com/sabus/OpenGlExamples