examples/gstreamer/filesrc.py,player.py: New examples

examples/gstreamer/filesrc.py,player.py: New examples

Original commit message from CVS:
* examples/gstreamer/filesrc.py,player.py: New examples

* gstreamer/gstreamer.override: Add a dict like interface to GstTagList

* gstreamer/gstpad-handlers.override: New file, split out from gstreamer.override

* gstreamer/gst-types.defs: Don't use
gst_buffer_free/gst_data_free, use gst_data_unref instead.

* gstreamer/gst-types.c (PyGstData_to_value): Don't send address here.

* gstreamer/arg-types.py (GstDataPtrArg.write_param): Send the
address to stuff, since we really want to avoid segfaults :)

* gstreamer/0.6.[c,defs,h,override]: Remove, we're focusing on 0.7

* gstreamer/0.7.[c,defs,h,override]: Remove, merge with
gstreamer.*

* gstreamer/Makefile.am: Clean up, remove versioning support.