SetVar and Decryption

Included in this release:

• SetVar Command: Fixed the Velocity translation for counting single variables.
• SetVar Command: Added the decrypt parameter.
• Commands: Added the DecryptInterface for commands with decryption capability.
• Translator: Added the createApacheVelocity() helper method.
• Parser: Added addParamString() to the statement info class.
• Docs: Added encoding and decoding examples.