Allow C4ScriptHost to load a script from memory

This will allow mape to feed the Map.c that is being edited directly to
the map generator.
Link C4MapScript into mape

Remove the two dependencies to ::Game from C4MapScript, so that ::Game
does not need to be linked into mape, which would basically drag the
whole rest of the engine after itself.
Allow MapScript generator to use non-global material and texture maps
mape: Add interface to run the new script map generator
mape: Default to the new map generator

Only use the C4MapCreatorS2, when the file is called "Landscape.txt".
mape: Add syntax highlighting for Map.c files
mape: Fix crash when InitializeMap() returns false
mape: Make sure error messages from the linker are shown
mape: Initialize script engine only once instead of per-rendering
mape: Also load syntax highlighting from current directory and repository
mape: Implement minimalist C4DefList
mape: Load the Library_Map script
mape: Set output window size to size of generated map

This is useful when a Map.c script specifies the size of the map.
mape: Re-initialize script engine between renderings

Otherwise there are warnings when the user changes the value of a
constant, since it was initialized with a different value at the
time of the previous rendering.
mape: Show rendering time in statusbar