Issue #2058371 by gordon: Re-port to Drupal 8 (.info.yml, controllers, cache service, ...)

In detail, this commit:
- Changes module info files to YAML (This allows to enable the module again)
- Changes the cache schema into a proper cache service
- Changes CSS_DEFAULT into CSS_AGGREGATE_DEFAULT because the constant was
  renamed
- Introduces a libraries_parse_dependency() function for the removed
  drupal_parse_dependency() (See https://drupal.org/node/2068797)
- Turns the libraries_test page callbacks into controllers
- Moves the libraries_test module
- Changes library info files to YAML