Show taskname in details dialog

[srguiwiz]

Also indicates whether that task is running.

The layout, alignment, padding etc. used for this in the details dialog should be revisited when switching to GTK 3.

Two goals had been:

• Allow the user to be sure what task they are looking at in the details dialog.
• Allow the user to quickly assert that task is still running, if user keeps the details dialog as their main view of the app during the workday.