Modify filename acceptance criteria with flags.

[lyda]

The Debian packaging standard has rules on acceptable filenames for files destined to cron.d. Enabling these with a flag would be better than the current solution.

http://www.debian.org/doc/manuals/maint-guide/dother.en.html#crond

When checking files in a package's debian/ directory, filenames should only match the (\S+\.)?cron.d as opposed to the other names currently accepted. In addition the error for this should probably point the user at the above link.

I suspect other packaging systems have their own standards, so need to investigate those first.

[daethnir]

Another vote for this. In our case we'd like to be able to lint crontabs that are in ansible and are preprocessed via j2, so we've named them all foo.j2. If we had an option to just ignore filename validation that'd be sufficient for us.