allow to check for links to "external" (non-sphinx-generated) files
Just found accidentally neglected bugreport in Debian bugtracker ( http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=546612 ):
Currently if ReST source links to some location on the same website, which was not generated by sphinx, e.g.:
.. _PDF-guide: PyMVPA-DevGuide.pdf
.. _API Reference: api/index.html
then linkcheck complaints:
index.rst:76: [malformed] PyMVPA-DevGuide.pdf
index.rst:78: [malformed] api/index.html
looking at CheckExternalLinksBuilder it seems to have no ability (yet) to check simply either that URI leads to some local file, which is indeed present, and thus is a legal link.
Patch I guess should be quite minimal (os.path.exists) or might be extended with checks either it is readable/available etc.