Switch to using url scheme wrappers instead of duplicating each command we wrap. The 'hg svn url' command has been killed; the replacement is '.hg/hgrc'. More stuff related to its disappearance has been stripped, including two tests. HgChangeReceiver now takes a UUID argument, which it uses to ensure that remote repositories remain unchanged. This is a temporary solution, and I'm not entirely satisfied with how it's done either. Access to the UUID file has been isolated in a HgChangeReceiver property. Some more tests have been updated to use ui.pushbuffer()/popbuffer(), and to pass through the Mercurial API. Moved the arguments to wrappers.pull() to the UI configuration. Also, remove HgChangeReceiver.opts in favour of a 'usebranchnames' instance & configuration variable. The name is taken from the ConvertExtension.

"""This is a special package because it contains (or will contain, as of now)
two parallel implementations of the same code. One implementation, the original,
uses the SWIG Python bindings. That's great, but those leak RAM and have a few
other quirks. There are new, up-and-coming ctypes bindings for Subversion which
look more promising, and are portible backwards to 1.4's libraries. The goal is
to have this file automatically contain the "best" available implementation
without the user having to configure what is actually present.
"""

#try:
#    # we do __import__ here so that the correct items get pulled in. Otherwise
#    # demandimport can make life difficult.
#    __import__('csvn')
#    from svn_ctypes_wrapper import *
#except ImportError, e:
from svn_swig_wrapper import *