Remove lwjgl dependencies from Texture
Create Headless and Base graphic-related assets

Inherit from BaseFont for common OpenGLFont behavior
Remove unnecessary per Immoritius lwjgl calls
Make ShaderManager an interface
Remove lwjgl dependency from NUIManagerInternal
Make GUIManager an interface
Make UIDisplayRenderer an interface
HeadlessCanvasRenderer for NUI
Make ShaderManager an interface
Version of Time without lwjgl refererences

Using the real clock may not be the answer to making this class work
Specify environment mode when starting Terasology
Add command-line option for specifying environment

Make Environment available from GameEngine

Set appropriate ShadeManagers

Fix where we used Display.getX/Y instead of Display.getWidth/Height

Clean up more Display references