- object updates were not being flushed, so children weren't updating.
- apply the matrix relative to the parent, added this as an option to object_apply_mat4() which allows assigning the worldspace matrix in python without worrying about the parent.
fix included in report from Martijn Berger (mberger)
made some small changes.
- use ints rather then unsigned long for printing, values are not likely to be very large.
- CMake remove strict flags from collada build dir since I had warnings in the collada headers.
- added xml2 to collada libraries else I couldnt get collada building.
