Convenient filter interface: Retrieve and filter request variable values

This package can retrieve and filter request variable values.

It provides an interface to retrieve GET, POST, REQUEST and COOKIE request variable values.

The main class can also validate and filter values according to several types like integers, booleans, floating point, numeric, e-mail address and URL.

It returns false when the request value is not of the expected type, or null if the parameter is undefined.

A separate class can mock request variables with given values.