Retro3d

- Project reorg to work better with Pypi
- Built separate sample projects: HelloWorld and Combat.
- Added requirements.txt
- Setup rez system for fonts/images/sounds
- Dumped some Si functions in favor of pygame functions
- Added cover/instruction/credits system
- Fixed 3d math bugs
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- Fixed issue of vertices that were behind the camera were being drawn
- Fixed normals - which was causing a dot product miscalc
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- Added safety check to Engine.__calc_face_color by making sure dot product parameter is in valid range
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- Support for hud drawing
- Added a shaded outline draw list
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- Added BackgroundInfo to support from flat to mutli-part-gradient backgrounds
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- Added game config
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