Fix a series of warnings in the engine code

This is a set of changes to remove some of the warnings in the engine code, there are still warnings left in the code stemming from protobuff, the test code, and one warning type in the engine. Still needs full testing.

There were quite a few variable defined that were unused, while some seemed just left over from development some look like physical or other constants. The latter were marked up with the keyword 'const' which at least prevents visual studio to warn about them.