tests/test-issue436

color/progress: subclass ui instead of using wrapfunction (issue2096)

This resolves the issue of hg cmd --mq not being colorized. This was due
to color wrapping only the instance of ui passed to dispatch._runcommand(),
which isn't the same ui object that mq.mqcommand() receives. After dispatch
calls extensions.loadall(), it makes sure any changes to ui.__class__ in
uisetup are propagated.

progress is updated to wrap ui in the same manner because wrapfunction
doesn't play well when ui.__class__ has been replaced by another extension
(orig will point to the old class method instead of color's).

#!/bin/sh

hg init a
cd a
hg -v log -v
hg -v log -v x
true