https://github.com/KhronosGroup/OpenCOLLADA/issues/188
https://github.com/KhronosGroup/OpenCOLLADA/issues/189
Fixing uniqueId serialization, fileId was ignored.
expose getInstanceControllerDataListMap() to get access to <skeleton>
Merge pull request #190 from KhronosGroup/fabrice-fixes

Fabrice fixes