Monkey patch anki at runtime

The server should work fine with /usr/share/anki now, as long as
external Anki version >= 2.1.

ankisyncd/__init__.py

@@ -1,2 +1,32 @@
+import functools
 import sys
+
+def __mediapatch():
+    """
+    Monkey-patch Anki's MediaManager to ignore the "server" attribute.
+
+    It's needed because MediaManager's __init__(), connect() and close() are
+    close to no-ops when self.col.server is True. If self.col.server is False,
+    Syncer.usnLim() doesn't match entities that are supposed to be sent to the
+    client, thus breaking server→client deck sync.
+    """
+
+    def noserver(f):
+        @functools.wraps(f)
+        def wrapped(self, *args, **kwargs):
+            orig = self.col.server
+            self.col.server = False
+            ret = f(self, *args, **kwargs)
+            self.col.server = orig
+            return ret
+        return wrapped
+
+    from anki.media import MediaManager
+    orig_init = MediaManager.__init__
+
+    MediaManager.__init__ = functools.wraps(MediaManager.__init__)(lambda self, col, _: orig_init(self, col, False))
+    MediaManager.connect = noserver(MediaManager.connect)
+    MediaManager.close = noserver(MediaManager.close)
+
 sys.path.insert(0, "/usr/share/anki")
+__mediapatch()