Improved GetComponent in OpenGLSystem

GetComponent now takes a component ID as well.

Also removed some uneeded items.
Added fullscreen toggle.

Fullscreen mode can now be toggled in IOpSys. It is currently only
implemented in win32 and SDL needs to still implement it.

Also CreateGraphicsWindow now takes window width and height parameters.
Adjusted GetWindowWidth/Height to return unsigned

GetWindowWidth/Height now return an unsigned value.

Implemented the win32 methods.
Fixed window width and height

Window width and height are not set to the desktop width and height for
fullscreen.

GetWindowWidth/Height also returns the current value depending on
fullscreen or windowed.
OpenGLSystem has viewport resizing

The viewport can now be resized to allow for runtime changes to render
screen size such as changing to full screen mode.

Also aspect ratio is now calculated using windowWidth/height.