EMI: Add specific detection for German Mac EMI
EMI: Add code for loading local.m4b from the german EFMI Installer file.
EMI: Add MD5 verification of the EFMI Installer file for german EMI
DOCS: Mention the necessary "EFMI Installer" file in Readme.md
EMI: Cache the entire contents of local.m4b to speed up the launch of the Mac version.

I did not remove the adding of local.m4b to SearchMan, as that for some reason blocked a few files from loading.
EMI: Add MD5 verification for the english mac installer thanks to clone2727
GRAPHICS: Allow FrameBuffer to manage its own texture
GRAPHICS: Allow guarded use of Graphics::Framebuffer

Raise an assertion if a framebuffer is requested without the correct
extension
GRAPHICS: Render to framebuffer [OpenGLS]
GRAPHICS: Render to framebuffer [OpenGL]
JANITORIAL: Fix style issues
GRAPHICS: Do not use framebuffers in AmigaOS
GRAPHICS: Draw the overlay above the game
GRAPHICS: Make sure the game only knows the size that's available for it to draw
GRAPHICS: Scale the mouse coordinates when drawing to a framebuffer
ENGINE: Add an engine feature to indicate an engine can render to any resolution
SDL: Use the desktop resolution for fullscreen when the engine supports it

Conflicts:
	backends/graphics/surfacesdl/surfacesdl-graphics.cpp
GRAPHICS: Clear the extensions list before initializing it

Graphics::initExtensions may now be called several times.
GRAPHICS: Probe system for GL_EXT_framebuffer_object

And disable the framebuffer functionality if it is not supported.
GRAPHICS: Store _aspect_ratio setting as instance variable