Fix support for cross-compilation, and fix handling of builtin libraries,
which would still attempt to link system libs and use system headers.
Also patch out GLU includes from GLEW, we don't need it, so that removes
another mandatory dependency.
-Fixed many bugs in stretch mode
-Fixes to camera project and unproject as consequence of the above
-added setget to script (documented in script doc)
-more fixes to collada exporter for blender
-=-=-=-=-=-=-=-=-=-=
Build System:
-Big clean up of SCons, changed how builds are done to a much cleaner method (check the Github Wiki for instructions).
-Deactivated BlackBerry10 (sorry), if no mantainer found (or BlackBerry does not send us a Passort ;), platform will be removed as we have no longer devices to test.
Engine:
-Removed deprecated object and scene format (was in there just for compatibility, not in use since a long time).
-Added ability to open scenes even if a node type was removed (will try to guess the closest type).
-Removed deprecated node types.
