Added new header "modules".

These files all include different parts of Splash Engine.
They can be thought of a modules.

For example, if you only want to include the bare minimum to run Splash
Engine, you would include "seBase.h".
Separated camera into two classes.

One for the basic camera, one for the fps camera.
Added a description comment box.

This displays the name of the file, who wrote it, the copyright notice,
and a small description.