phabricator: include commit (node) and parent in the local:commits metadata

Differential Revision: https://phab.mercurial-scm.org/D6298

hgext/phabricator.py

@@ -399,6 +399,8 b' def writediffproperties(ctx, diff):'
                 b'author': stringutil.person(ctx.user()),
                 b'authorEmail': stringutil.email(ctx.user()),
                 b'time': int(ctx.date()[0]),
+                b'commit': ctx.hex(),
+                b'parents': [ctx.p1().hex()],
                 b'branch': ctx.branch(),
             },
         }),