obslog: make {descdiff} not be indented and leave that to the template Same idea as the previous patch and same explanation for changes to the test case.

obslog: make {patch} not be indented and leave that to the template This removes some unwanted indentation from the tests. In the first case, it's because indent() doesn't indent a blank line. In the second case, it's because we used templating with {patch} and had not requested indentation (but we still got it before this patch). Note that tests will only pass with a very recent Mercurial (one with https://phab.mercurial-scm.org/D7432 applied).

obslog: make {succnodes} be full hex nodes It should be up to the user to shorten the nodeid as much or as little as they like.

obslog: remove now-unused code for plain styling We now always use a non-plain formatter for the non-local-filtering code paths, so we can remove the code for plain styling. I couldn't figure out how to replace the fm.formatlist() by something less about formatting, so I've only removed the irrelevant arguments from those calls.