journal: use pager

journal output is long and should use a pager.

Differential Revision: https://phab.mercurial-scm.org/D1740

hgext/journal.py

@@ -480,6 +480,7 b' def journal(ui, repo, *args, **opts):'
 
     limit = cmdutil.loglimit(opts)
     entry = None
+    ui.pager('journal')
     for count, entry in enumerate(repo.journal.filtered(name=name)):
         if count == limit:
             break