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.
add scriptaliases parameter for multiple script aliases

closes #368
Merge pull request #422 from igalic/mod-php-deps

satisfy mod_php inter-module dependencies
Merge pull request #394 from jlambert121/issue_368

(#368) Add scriptaliases parameter for multiple script aliases