Correct broken mime_magic config for Debian

The location "conf/magic" in the mime_magic.conf template is RedHat specific
and is broken under Debian/Ubuntu. Added a class parameter with an os agnostic
default and matching template usage.

Added full testing and updated `README.md` to indicated this module has
settings and template parameters.
Merge pull request #421 from dbeckham/mime_magic_ubuntu_fix_squashed

Correct broken mime_magic config for Debian - Squashed commit for #418
satisfy mod_php inter-module dependencies

we try to make sure that mod_php's inter-module dependencies (mod_dir
and mod_mime) are satisfied before we try to implement any changes in
the config that would trigger those.
This fixes #408.
Merge pull request #422 from igalic/mod-php-deps

satisfy mod_php inter-module dependencies