Improve support for moved files in diff commands. Now we only check for moved files if we get an empty diff/cat output from the normal codepath. We also do that for both sides of a diff, and for the diff-summary commands.

changeset = '{rev}:{node|short}{bookmarks}{tags} {desc|firstline} (by {author|user}, {date|localdate|age})\n'

start_bookmarks = ' '
bookmark = '+{bookmark}'

start_tags = ' '
tag = '#{tag}'