Detour: Prefixed static nav with 'dtStat', this includes polys and poly refs too.
imgui: Made imgui code not to use id:s anymore, since there were way too many id clashes.
imgui: Separated the rendering code into its' own file, changed prebaked font to use stb_truetype instead, removed glfont.
imgui: Added 'disabled' property to widgets.
Recast: exposed single triangle rasterization into the recast api.
Demo: Changed the debug draw validation to be "soft", easier to demo now.
Rewrote fixup contours, now should handle all cases.
Added few more debug draw modes for the demo.
Changed the vertex welding to cope with slight imprecision in y-direction.
