Provide way to save and save as and prevent overwriting concern models

[Matthias Schoettle]

Currently, it is only possible to perform a "save as" in TouchCORE.

Instead, it would be better to have two options:

• save saves the current aspect and its associated concern
  • if the aspect is new and hasn't been saved before, the save as dialog will appear
• save as presents the file chooser and then saves the aspect and its concern
  • existing concern models should not be allowed to be overwritten in order to prevent inconsistencies of links between the .core and .ram files

[Cécile Camillieri]

Do you mean that we don't want to be able to "save as" existing models at all? If so, the issue is already resolved since the new menu was introduced (#315)

[Matthias Schoettle]

Yes, the first part was alreado done in #315.

Not sure if we need "save as" anymore. However, sometimes it's nice to be able to save into a different file to not overwrite the existing one, e.g., for testing purposes...