This is something that really should be done in higher level code - the shader interface should only concern itself with the shader and not the conditions that block its use.
The Shader class has been redone as a thin wrapper and been deprecated.
* it is now possible to switch back to the main intro loop from the fullscreen console.
* do not distort the background of the fullscreen console. Always draw the console on top of what the main loop currently displays with a translucent black overlay.
* do not use the CONPIC for the fullscreen console as it tends to be more of a distraction than an asset when filling the entire screen.
* cleaned up c_console.cpp and moved several pieces of code unrelated to actual console management out of it.
