Minor mesh class improvements.
GetParentTransforms is now public (again).
Batch groups now working.

Batch groups are now working for meshes.

Using a stress test, I was getting 14 fps without batch groups. With
batch groups, the fps jumped up to 70.
Added a (semi-broken) 3D sound class.
Added a logging class.

For all your debugging needs.
Time class can now get system time & date.
Removed unused commented code.
Debug log now used instead of console.
New optimization header file.