Some cleanup, and update to make those files usable both as self-executables and module stuff...

Also updated update_mo to allwo specifying a custom po/mo file.

release/scripts/modules/bl_i18n_utils/update_po.py

@@ -28,8 +28,12 @@ import sys
 from codecs import open
 import shutil
 
-import settings
-import utils
+try:
+    import settings
+    import utils
+except:
+    from . import (settings, utils)
+
 
 GETTEXT_MSGMERGE_EXECUTABLE = settings.GETTEXT_MSGMERGE_EXECUTABLE
 BRANCHES_DIR  = settings.BRANCHES_DIR