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
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
ls
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "1000000 0"
hg co 0
# B should disappear
ls