Refs #46, #60, #71 - Fragments implemented with tests

See merge request !133

Refs #46, #60, #71 - Fragments implemented with tests

See merge request !132

Refs #46 - Fix index.php when it needs to generate error on the fly, so that the meta can be passed by reference.

Refs #46 - Update core to work purely with meta as an associative array, implement pre-processing of fragments.

Refs #46 - ResourceValidator: change order of type detection to account for boolean correctly being detected as float or int.

Refs #46 - ResourceValidator: limitProcessors not to validate processor type when nested in an array.