qfold: allow to specify '--message/'--logfile' and '--edit' at the same time

Before this patch, 'hg qfold' disallows to specify
'--message/'--logfile' and '--edit' at the same time.

'hg qfold' has disallowed such combination since Mercurial 0.9.2, but
this restriction seems not to be reasonable for recent Mercurial,
because all other commands creating new changeset allow it.

This patch allows 'hg qfold' to specify '--message/'--logfile' and
'--edit' at the same time like other commands creating new changeset.

hgext/mq.py

@@ -2546,9 +2546,6 b' def fold(ui, repo, *files, **opts):'
     q.checklocalchanges(repo)
 
     message = cmdutil.logmessage(ui, opts)
-    if opts.get('edit'):
-        if message:
-            raise util.Abort(_('option "-e" incompatible with "-m" or "-l"'))
 
     parent = q.lookup('qtip')
     patches = []

tests/test-mq-qfold.t

@@ -174,10 +174,11 b' Test saving last-message.txt:'
   $ hg tip --template "{files}\n"
   aa
 
-(test that editor is not invoked before transaction starting)
+(test that editor is not invoked before transaction starting,
+and that combination of '--edit' and '--message' doesn't abort execution)
 
   $ rm -f .hg/last-message.txt
-  $ HGEDITOR="sh $TESTTMP/editor.sh" hg qfold -e p3
+  $ HGEDITOR="sh $TESTTMP/editor.sh" hg qfold -e -m MESSAGE p3
   refresh interrupted while patch was popped! (revert --all, qpush to recover)
   abort: emulating unexpected abort
   [255]