add a magic resource list that prevents duplicate mime-types from

being added... probably should add more matching, but this is good
for now...

[git-p4: depot-paths = "//depot/": change = 1130]

DIDLLite.py

@@ -32,6 +32,21 @@ class Resource:
 
 		return root
 
+class ResourceList(list):
+	'''Special class to not overwrite mimetypes that already exist.'''
+	def __init__(self, *args, **kwargs):
+		self._mt = {}
+		list.__init__(self, *args, **kwargs)
+
+	def append(self, k):
+		assert isinstance(k, Resource)
+		mt = k.protocolInfo.split(':')[2]
+		if self._mt.has_key(mt):
+			return
+
+		list.append(self, k)
+		self._mt[mt] = k
+
 class Object(object):
 	"""The root class of the entire content directory class heirachy."""