Remove denyhosts.conf template in favor of a config hash

Rather than maintain an evolving template and associated attributes, this PR introduces a hash that gets iterated and written out to disk. In this way, one may simply add/create an attribute to manipulate the DenyHosts configuration - no template modification required.

The majority of the DenyHosts config documentation is in the configuration file itself. I have moved an abridged version of those comments to the attributes file. I have also updated the documentation to reflect all currently known attributes.