undo-files: cleanup legacy files when applicable
The "journal" code is much more compact in 6.4, and so is the "undo" files as a
result. However the previous version were much noisier, so let us cleanup undo
files from older version too.
#require test-repo jshint hg10
$ . "$TESTDIR/helpers-testrepo.sh"
run jshint on all tracked files ending in .js except vendored dependencies
$ cd "`dirname "$TESTDIR"`"
$ testrepohg locate 'set:**.js' \
> 2>/dev/null \
> | xargs jshint