evolve: adapt for deprecated ui.progress()
This makes a wrapper that has an interface like ui.progress() even
though that's the old interface that will eventually go away. That's
because it's a lot easier to convert from the ui.progress() to the
ui.makeprogress() interface than the other way around. Once we no
longer support hg<4.7, we can migrate our callers to ui.makeprogress()
and drop the wrapper.