API changes

As unit test coverage increases, APIs change.

The Input class itself shares its data access methods with the InputData class for ease of use and quick on-the-fly data access.

Accessing data is done using ArrayAccess now, rather than property access, due to the StyleGuide specifying "Only properties should be used when a predefined set of data attributes can be determined".

Input class fully tested

The basics are working. The Input class can be constructed from the $_GET, $_POST and $_FILES arrays. with(), without(), withAll() have been tested when calling them on the Input class themselves, and the correct callbacks are called.