0.2.0: Compatibility with "real" Map.c

ocmapgen now does most things the Map.c in the OC repository require:

• It generates default SCENPAR constants from ParameterDefs.txt
• It loads the top-level System.ocg (but not scenario-level ones, those usually depend on definitions)
• It implements GetStartupPlayerCount() and GetStartupTeamCount()
• It loads materials from overloaded Material.ocg

(Mape only does the last point!)

Other improvements:

• Non-cryptic error reporting, including multiple lines of script errors
• --watch switch for the CLI enables automatic recompilation on save
• Map background export
• Saving as indexed BMP which is usable as static map