builddependencies: don't add dependency on revision outside input set
This was already handled in the single-successor case, but had been
missed in the multiple-successors case.
Note that there seems to be a copy of builddependencies() in the
topics extension. I don't use topics more than I have to, so I'll let
someone else fix that code.
syntax: re
/figures/[^/]+\.png$
^html/
\.pyc$
~$
\.swp$
\.orig$
\.rej$
^tests/.*\.err$
^tests/easy_run.sh$
^build/
^dist/
^MANIFEST$
^docs/tutorials/.*\.rst$
\.ico$
tests/\.testtimes
^docs/training/graphs/
^docs/training/html/
^docs/training/index.html
^docs/training/graphviz-images/
^docs/training/img/
^docs/training/output/
^docs/training/pandocfilters/