ImportScripts: _buildPatch and _scanModFile:

ImportFactions: added some comments to mark where I need to change so
I can use _scanModFile
Added id_data = None # noinspection PyUnusedLocal.
NB: now applies to all patchers that use _scanModFile - can't be bad
methinks.

[fixed: had a bug originally - indented `id_data = None` inside the loop]