help: deprecate ui.slash in favor of slashpath template filter (
issue5572)
> For some reason, I thought someone (Mads?) said we had basically given
> up on ui.slash, and some commands didn't support it.
(from https://bz.mercurial-scm.org/show_bug.cgi?id=5572#c1)
So the ui.slash option doesn't always work and is somewhat confusing. Let's
make it clearer we won't improve the situation.
templatefilters: add slashpath() to convert path separator to slash
Prepares for deprecating the ui.slash option, which isn't always respected.
check-code: remove unused variable 'winglobmsg'
Follows up
5feb782c7a95.