contrib/wix/hg.cmd

pycompat: add util.urlerr util.urlreq classes for py3 compat

python3 url.request and url.error are mapped as util.urlreq/util.urlerr
python2 equivalents from urllib/urllib2 are mapped according to the py3
hierarchy

@echo off
rem launch hg.exe from parent folder
"%~dp0\..\hg.exe" %*