Consider changing "Delete job" to "Close job"

[bertfrees]

While "Delete job" is a correct description of what happens (should happen) to the job within the engine, it might not be the best from a user perspective. Because the results are automatically stored in the results folder, the user might fear that the results would be deleted too. I can think of the following solutions:

• Perhaps a better name is "Close job"? Note that when we add persistence in the future, closing a job tab and deleting a job from the engine will be strictly different things anyway.
• When a job tab is closed we could show a warning that the job is deleted from the engine, but that the results in the results folder are not deleted. (Perhaps it is better to not even mention the engine for now.) There could be a "Don't show this message again" option (and when the whole window with more than one completed jobs in it is closed (#83) there could be an option to confirm once for all jobs).
• There could be a similar message in the help text / title attribute of the button.

[bertfrees]

Done, but the "close" terminology is not consistently used everywhere yet. E.g.:

• in the warning messages that are presented before a job is closed
• in the settings window

[bertfrees]

Shall we reopen this issue? Or create a new one?

[bertfrees]

Reopening it.