show: add basic labels to work template `hg show work` is much more usable if output is colored. This patch implements coloring via label() in a very hacky way. In a default Mercurial install, you'll see yellow node labels for all phases. Branches and bookmarks use the same formatting as the commit message. So this change doesn't help much in a default install. But if you have a custom colors defined for these things, output is much more readable. The implementation obviously needs some work. But for a minor change on a feature that isn't convered by BC, this seems like a clear win for the feature in 4.2.