Merge pull request #3 from overplumbum/master

Accept filenames used in Debian packaging.

According to the Debian packaging guides, files named debian/foo.cron.d will be installed as /etc/cron.d/foo. Files named debian/cron.d are also allowed - the cron.d file is given the package name in /etc/cron.d. For more info: http://www.debian.org/doc/manuals/maint-guide/dother.en.html#crond

In order to check these files during the packaging phase, files matching (\S+\.)?cron.d must be allowed.

At a later point it is probably a good idea to have these filename extensions enabled by flags. As the comment preceding the code alludes to, some names that run-parts would not accept are already allowed for another file deployment system.

I'll do that later after I review some other packaging system docs.