Allow for more than one changelog file name
When no changelog file name is found in the config, more than one default name should be searched, possibly all of (CHANGES|CHANGELOG)(|.txt). Ordering is not a concern and if more than one of the files is found with changes, the user should simply be out of luck.
Also, the config setting should expect more than one file name to be listed. This would be good for configuring user defaults in ~/.hgrc.