Be more graceful if DMX isn't available

factory.py

@@ -48,6 +48,8 @@ class MakeSet:
 
 class MakeFixtureTypes:
     def __new__(cls, config):
+        if config is None:
+            config = []
 
         def parse_range(src):
             (a, b) = src.split('-')
@@ -77,6 +79,8 @@ class MakeFixtureTypes:
 class MakeFixtures:
     def __new__(cls, config, fixture_types):
         fixtures = {}
+        if config is None:
+            config = []
         for fixture in config:
             dmxch = config[fixture]['dmx']
             type = config[fixture]['type']
@@ -88,6 +92,8 @@ class MakeFixtures:
 class MakeGroups:
     def __new__(cls, config, fixtures):
         groups = {}
+        if config is None:
+            config = []
         for group in config:
             fobjects = []
             for fixture in config[group]:
@@ -101,6 +107,8 @@ class MakeGroups:
 class MakeScenes:
     def __new__(cls, config, fixtures, groups):
         scenes = {}
+        if config is None:
+            config = []
         for scene in config:
             objects = {}
             for name in config[scene].keys():