progress: display progress bar when HGPLAINEXCEPT contains "progress"
This patch changes "progress.shouldprint()" so a feature name is provided to
"ui.plain()" to determine if there is an exception specificed in HGPLAINEXCEPT
for the progress extension.
This will allow user-facing scripts to provide progress output while HGPLAIN
is enabled.
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init
$ echo 'base' > base
$ hg ci -Ambase
adding base
$ hg qnew -mmqbase mqbase
$ hg qsave
$ hg qrestore 2
restoring status: hg patches saved state