revset: undocument wdir() until its command outputs get stable
wdir() implementation is still incomplete and shouldn't be advertised to
users. This patch will be backed out when
- template values such as {rev} and {node} are settled
- major commands and revsets work without crashing
linkrev: fix issue with annotate of working copy
The introrev was appearing as None in new annotate tests, which the
code from the stable branch wasn't expecting.