Process refactoring

Here is the work in progress we did with RP concerning the process refactoring.

We essentially focused for now on medAbstractProcess, job item (renamed medAbstractJob) and on the filtering workspace.
Basically, the idea is now that the process is able to provide its toolbox and the containers he needs.
The workspace when setting up a new process retrieves the containers and set up the area.

To demonstrate this,  we created a new filter that takes 2 inputs and subtract the second image to the first one.

medAbstractProcess is not finished yet, but it will give a good idea of where we think we should go.

RP & GP