System Architecture rework

[LeonMatthes]

Currently the roles of the main classes (controller, context, menu and models) are pretty mixed into each other.
They should however all perform just one role, these should be:

Controller
Responsible for directing user input, to open/close the menu and to provide the menu with the appropriate model.
Currently the controller is Smalltalk-specific, there are even subclasses for browsers and workspaces, that provide functionality that should probably belong to the context.

Current sins:
#allowOverriding, #completionAdditionals, keeps a permanent reference to the context

Context
The context should be responsible for detecting in what context Autocompletion was opened.
Is there a receiver? What class is it? etc.
Therefore this should be the first Smalltalk-specific part of the system, not the controller.
The context should then be the first part that the Textfield-Model has controller over, basically deciding whether it is a Smalltalk-Textfield or something else.
This would make it possible to implement #23
The context should therefore also be the one responsible for checking whether it is parsing a method, not the controller.

Possible sin: Contains a reference to the model, not necessarily a problem, but who knows

Model
The Model is responsible for collecting all the entries, storing and filtering them
There should be Smalltalk-specific models as well as general purpose ones.

Current issue: Pretty slow, otherwise the models code is pretty solid.

Menu
The menu is responsible for displaying the model data.
It should be as smalltalk-agnostic as possible.

Current sins: Keeps a permanent reference to the context which it uses to access the model instead of communicating with the model directly.
Refactoring needed to remove the context from the model

[LeonMatthes]

New questions:
Who is responsible for switching to untyped?
This is currently done by the menu morph, but should rather be a feature of the Controller, which could just reopen the menu to refresh it.
That would however make the controller smalltalk-specific again..
But thats not too bad as the feature could just be ignored in a non-smalltalk context.