obslog: add a patch option Add support for '--patch' option in obslog for a similar effect than "hg log --patch". The patch support is only limited to a few basic cases that will be extended in the future.

syntax: re
/figures/[^/]+\.png$
^html/
\.pyc$
~$
\.swp$
\.orig$
\.rej$
\.err$
^tests/easy_run.sh$
^build/
^dist/
^MANIFEST$
^docs/tutorials/.*\.rst$
\.ico$
tests/\.testtimes