My Validation: Validate request values according to custom rules

This class can validate request values according to custom rules.

It can take request values from different sources to perform several types of validation.

Currently it can validate values sent via GET or POST requests, session variables, cookie values and global variables.

The class takes another parameters that defines the type of validation condition to be evaluated.

Currently it can evaluate if the value is a number that is equal, different, smaller or larger than a parameter, check if it is within a range or in a list of values, if it is a float, an email address, a date, or matches a regular expression, etc..