Secure Data: Encrypt and decrypt data with mcrypt Rijndael 256

This class can encrypt and decrypt data with the mcrypt extension using the Rijndael 256 algorithm.

It can take a string of data and encrypt it using the Rijndael 256 algorithm.

The result is encoded with the base64 algorithm so it can be stored as text.

The class can also do the opposite, take previously encrypted data, decode the base64 encoded data and decrypt it using the same algorithm.