Filtreatment: Validate and filter text values based on rules

This class can be used to validate and filter input values based on several types of rules.

It can treat a text value by performing one or more several types of validation. Each validation returns the filtered value or false if the input is not valid.

Currently the class can perform the validations for: integer values, floating point values, strip HTML tags, regular expression matching, e-mail address, HTML without potential cross site scripting (XSS) exploits, and escaped text values for SQL queries to avoid SQL injections.