new revision - cisco_ironport_enum

Added code to check successful conn first, so now if there is no connectivity on target port, script aborts run.
New check to ensure 'set-cookie' is set by the app as expected, before any further fingerprinting & b-f starts.
If the app is not Ironport, 'set-cookie' will not be set & remains null, and so script aborts run.
De-registered 'TARGETURI.'
Registered 'username' and 'password' with default value.
Changed some run messages.
And lastly, changed the csrf key piece cos I miss a cold beer right now.