deal with files related to apache modules

Hi Alessandro,

thx for this great puppet-apache module. I wrote a little extension because some apache modules require some more files beside the *.conf file (e.g. ssl certificates for the ssl module). It would be nice to have them connected to the apache::module definition. This branch contains a first draft to do that. So far, I only tested it on RHEL. But it will probably work on Debian systems as well. Looking forward to your feedback! I am not yet sure, if it is better to have a separate definition block for the additional files (beside the configuration file) or to integrate this extension into the apache::module definition. The former allows to attach several additional files to a module definition. I can't imagine any way how to achieve this with an integrated solution. However the latter shortens the final puppet recipes which use the apache::module definition with additional files.

Regards
Sarah