#5704: Econda tracking of user registrations is faulty.

Formatting code
#5704: Econda tracking of user registrations is faulty.

Creating pages contents and order step names for later usage in getCode() method instead of using strings inside the method.
#5704: Econda tracking of user registrations is faulty.

Refactoring getCode() method to few smaller methods and making it to use $_aPagesContent and $_aPagesContent instead of string straight in the methods.
#5704: Econda tracking of user registrations is faulty.

Moving public methods to the top.
#5704: Econda tracking of user registrations is faulty.

Making createUser() method to redirect to payment step with parameters, showing that new user was created before redirection.
These parameters will be used in oxemosadapter to correctly track user registrations.
#5704: Econda tracking of user registrations is faulty.

Adding tracking of user registrations in payment step.
#5704: Econda tracking of user registrations is faulty.

Changing deprecated function to new one.