[pymapistore]: Fix get_properties behaviour (no arguments returns available properties, empty list returns no properties)
[mapistore-python]: Add return value check and memory allocation in get_available_properties
[pymapistore]: Correct MID assignation in folder.c
[pymapistore]: correct input type for py_MAPIStoreFolder_create_folder
Merge pull request #129 from icandigitbaby/mapistore-python-fixes

Fixes in mapistore_python.c and MAPIStorePython bindings