This means we can do operator drawing without passing self.properties as an argument.
while this check if quite specific, if this gives problems later on we should probably change operators not to try to mix an operator and its properties, it looks nice to a scripter but internally is not easy to manage.
- made operator dir's into python packages
- lazy loading of module which do the actual import and export (faster blender load times)
- general maintanance and small fixes.
- bugfix for exporting x3d materials
- leak fix for exporting 3ds
