GUI: Improve archetype creation (oasp4j create)

[hohwille]

Category: enhancement

Severity: Medium

Description of issue / expected enhacement /Comments:
I used the GUI for archetype creation with devcon and I like it. However, here are my suggestions for improvement:

[Jan-PeterRichterCG]

Another improvement:
As of March 2019, devcon locks up the dialog if a validation error occurs. Click on Start when not all fields are filled and try to correct your mistake!

By the way: the devcon should also give its own version in a "about devcon" dialog.