Python isn't used during the build, only for the installed event_rpcgen.py
script, which supports both Python 2 and 3 for some time now.
And since our switch to python beaing python3 we were usign Python 3 anyway.
* Adds transmission bittorrent client using gtk3
* Updates libevent (dll version bump, but nothing depends on it)
and add patch from upstream transmission. Otherwise tracker
connections fail.
* More of the included libraries could be packaged separately,
but this is a start..
