Finalise the Signal-Encryption plug-in and bring merge it into the upstream

[tassadarius]

Currently, the Signal plugin done by students in Hagenberg is done by ~80%.
However, we need to finish it, following main tasks are still to be done:

• Finalise UI
  • Remove keys in first tab
  • Add key information in second tab
• Translate Plugin into English
• Create Online-Help in German/English

Optional improvements:

• UI
  • (2nd tab) Replace hard coded steps text fields at top with a single text field
  • Currently, multiple Canvases are used. This is unnecessary. Better would be one single Canvas into which all arrows are drawn (remember that Canvas inherit from Composite and can be used as normal Composite also!)
  • Give visual indications between operations and values in the flow chart. (e.g. the DH public key and the key calculation have the same box, which is unintuitive.

Overall, I would say it's still quite some work to do, especially the Online-Help.
I would estimate it in May to be done.

[tassadarius]

I recreated a new ticket, since this was kind of old, see #376