This is some loose scrabbling made by TobiX, they might eventually be relevant
for 2.1.

INTERFACES, in general

should:

- provide the user (client?) with a list of possible actions (methods).
- let the user execute those actions (methods).
- Return information to the user/client.

There are two kind of actions/methods:

- Information retrieval
- Transactions

For the first, I think the best thing is to just provide a lot of
methods for it in the libraries, and let it be an Interface Design
Issue what to show and how to show it.

For the second, I think we can win in the long run on having a
generalized methods for 

- listing transaction types.
- creating & committing transactions.

..with the possibility of just deploying new custom-developed modules
when new transaction types are needed.


$RT::TransactionTypes  ...and...
%RT::TransactionTypes
   - global object which contains all TransactionTypes
   - used by all UIs to create menues of possible (user) actions (one TransactionType is a user action)

The UIs should call sth like
$Ticket->AddTransaction($TransactionName), which should be equivalent
with i.e.  $Ticket->Correspond when $TransactionName is 'Correspond'
(AUTOLOAD should call the do-sub if exists
$RT::TransactionTypes{$TransactionName})

The RT::Ticket::AddTransaction will create a new transaction of the
right TransactionClass (maybe via a sub
RT::TransactionTypes::NewTransaction).  Then $Transaction->do is
called.

TransactionType->do initializes a new object of the right TransactionClass, and