Add new params to apache::mod::mime class

This changeset adds $mime_support_package and $mime_types_config
parameters to class `apache::mod::mime`. Their purpose is following:

- $mime_support_package - install this package, as it provides mime.conf
  file (definition of mime types used by mod_mime),
- $mime_types_config - used to substitute TypesConfig in
  mod/mime.conf.erb template.

This PR was created in order to plit #342 into smaller
parts to make review process easier, see
https://github.com/puppetlabs/puppetlabs-apache/pull/342#issuecomment-25423813
Merge pull request #447 from ptomulik/mod_mime_params

Add new params to apache::mod::mime class