`Card` now has a `make` method, and a `setCard` method.
Completed the constants list for PayGate returns.
Implemented a `thread` method to allow for own MPI use.
Renamed some private properties and methods (mainly `Url` to `URL`).
`clearTransaction()` will no longer clear the card and transaction settings. Only the returned values, and will now reset `complete` to false.
`make` will now clear the transaction regardless of it's completion state.
`card()` now only accepts a `Card` instance.
Added a `getCard()` method to grab the card instance.
Most methods will clear the transaction data if they are called after a completed transaction.
`payer()` will determine the IP automatically if not specified.
`submit()` and `preauth()` will throw an exception if called on an completed transaction.
`settle()` and `refund()` will throw exceptions is not passed a transaction ID, or called on an incomplete transaction.
Added a `complete()` method.
`requiresAuthentication()` will now return `NULL` if called against an incomplete transaction.

Added a readme.me