Rip out all code that directly uses gstreamer

We can now rip CDs without gstreamer.

This is not the most clean attempt, but I have tried to remove most of the
code that depends on gstreamer. I hope there is not a lot of code left that
depends on code that I have removed - I can at least rip a CD fully.

morituri/common/common.py

@@ -135,47 +135,6 @@ def formatTime(seconds, fractional=3):
 
     return " ".join(chunks)
 
-
-def tagListToDict(tl):
-    """
-    Converts gst.TagList to dict.
-    Also strips it of tags that are not writable.
-    """
-    import gst
-
-    d = {}
-    for key in tl.keys():
-        if key == gst.TAG_DATE:
-            date = tl[key]
-            d[key] = "%4d-%2d-%2d" % (date.year, date.month, date.day)
-        elif key in [
-            gst.TAG_AUDIO_CODEC,
-            gst.TAG_VIDEO_CODEC,
-            gst.TAG_MINIMUM_BITRATE,
-            gst.TAG_BITRATE,
-            gst.TAG_MAXIMUM_BITRATE,
-            ]:
-            pass
-        else:
-            d[key] = tl[key]
-    return d
-
-
-def tagListEquals(tl1, tl2):
-    d1 = tagListToDict(tl1)
-    d2 = tagListToDict(tl2)
-
-    return d1 == d2
-
-
-def tagListDifference(tl1, tl2):
-    d1 = tagListToDict(tl1)
-    d2 = tagListToDict(tl2)
-    return set(d1.keys()) - set(d2.keys())
-
-    return d1 == d2
-
-
 class MissingDependencyException(Exception):
     dependency = None