http: fix many problems with url parsing and auth. added proxy test. problems fixed: - https scheme handled properly for real and proxy urls. - url of form "http://user:password@host:port/path" now ok. - no-proxy check uses proper host names.

#!/bin/sh

hg init
python -c 'print "confuse str.splitlines\nembedded\rnewline"' > a
hg ci -Ama -d '1 0'
echo clean diff >> a
hg ci -mb -d '2 0'
hg diff -r0 -r1