* Fix var declaration in bpy_interface.c
* Remove forward declarations from py_capi_utils.h: they are unnecessary and break compiles (there were probably many warnings about this during compile with GCC).
- ID properties now suopport non utf-8 strings for their values but not their keys.
- moved utility functions into py_capi_utils.c from bpy_utils and bpy_rna.
- import/export paths have to be printed with repr() or %r, so non utf-8 chars are escaped.