js.py: Add option to filter sources from another module

This is so we don't have to worry about including dependencies in the
main reddit.js module that have already been included in reddit-init.js.

r2/r2/lib/js.py

@@ -127,6 +127,11 @@ class Module(Source):
         self.should_compile = kwargs.get('should_compile', True)
         self.wrap = kwargs.get('wrap')
         self.sources = []
+        filter_module = kwargs.get('filter_module')
+        if isinstance(filter_module, Module):
+            self.filter_sources = filter_module.get_flattened_sources([])
+        else:
+            self.filter_sources = None
         sources = sources or (name,)
         for source in sources:
             if not isinstance(source, Source):
@@ -146,6 +151,9 @@ class Module(Source):
                 s.get_flattened_sources(flattened_sources)
             else:
                 flattened_sources.append(s)
+        if self.filter_sources:
+            flattened_sources = [s for s in flattened_sources
+                                 if s not in self.filter_sources]
         return flattened_sources
 
     def get_source(self, use_built_statics=False):
@@ -572,6 +580,7 @@ module["reddit"] = LocalizedModule("reddit.js",
         "moderator_invite": ModeratorPermissionSet,
     }),
     wrap=catch_errors,
+    filter_module=module["reddit-init-base"],
 )
 
 module["modtools"] = Module("modtools.js",
@@ -592,7 +601,8 @@ module["admin"] = Module("admin.js",
 module["mobile"] = LocalizedModule("mobile.js",
     module["reddit"],
     "lib/jquery.lazyload.js",
-    "compact.js"
+    "compact.js",
+    filter_module=module["reddit-init-base"],
 )