stack: demonstrate that not reusing cached property gives different results
Instead of using self._dependencies, which is a cached property, let's get
fresh deps and rdeps in stack.revs method using a newly introduced
stack.builddependencies method (will be removed in the next patch).
This makes it easier to explain why the next patch is correct.
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/