0.5.0_pre: Merge pull request #39 from Tridify/fixed_opencollada_revision

These are Unofficial Windows Snapsots of the 0.5.0 development cycle of IFCOpenShell-Python built against Python 2.7 and are targeted for use with FreeCAD, although they should work with a standard Python27 distribution. Copy the extracted ifcopenshell folder to the site-packages sub-directory of the appropriate Python distribution. They support Windows Vista/7/8/10.