revsfromrange: remove reference to '_revs' in merge slicing
Given '_revs' is a property from the cache, we use the official method of the
object we are on instead. That method should be using the same cache than the
property if available.
syntax: re
/figures/[^/]+\.png$
^html/
\.pyc$
~$
\.swp$
\.orig$
\.rej$
\.err$
^tests/easy_run.sh$
^build/
^dist/
^MANIFEST$
^docs/tutorials/.*\.rst$
\.ico$
tests/\.testtimes