mq: fix opts['unified'] = '0' to take effect when qdiff --stat
`opts['unified'] = '0'` tries to reduce the number of lines to be
processed by patch.diffstat, but here it does not affect diffopts,
thus it does not make sense.
Instead, we can change `diffopts.context` directly.
Added test case for qdiff --stat.
#!/usr/bin/env python
#
# An example hgweb CGI script, edit as necessary
# Path to repo or hgweb config to serve (see 'hg help hgweb')
config = "/path/to/repo/or/config"
# Uncomment and adjust if Mercurial is not installed system-wide:
#import sys; sys.path.insert(0, "/path/to/python/lib")
# Uncomment to send python tracebacks to the browser if an error occurs:
#import cgitb; cgitb.enable()
from mercurial import demandimport; demandimport.enable()
from mercurial.hgweb import hgweb, wsgicgi
application = hgweb(config)
wsgicgi.launch(application)