Empty XMLRPC response from launchpad

[Gordon Tyler]

I've pushed my fixes to a branch on launchpad: lp:~doxxx/bzr/lp_proxy. 
It uses bzrlib's urllib2 wrapper classes to provide an alternate 
Transport for xmlrpclib. This seems to have solved the weird redirect 
issue I was having earlier.

I also fixed a few unguarded calls to self._report_activity in the 
urllib2 wrappers' _ReportingFileSocket and _ReportingSocket classes that 
were causing problems for me.

I've tested this at home using tinyproxy installed on a Debian box, with 
the bzr client on a Windows box. Unfortunately, in the firewalled & 
proxied corp environment, it's now failing with a 502 Proxy Error which 
I still have to figure out.

Ciao,
Gordon