Various cleanup and optimization
- Deleted shameful dead code here and here...
- Accelerated creation of GenBitmap*Button adding some caching for bitmap grayOut
- Replaced lists inside type use dictionary by sets
- Prevented useless type usage checking when unnecessary

import os
from POULibrary import POULibrary

class NativeLibrary(POULibrary):
    def GetLibraryPath(self):
        return os.path.join(os.path.split(__file__)[0], "NativeLib.xml")