Have focus-stealing modal dialogs ignore "always on top" rule of other windows

[Peter Parker]

Mantid does not accept any mouse input under a certain set of circumstances and has to be closed unless the Alt+F4 keyboard shortcut is used. To reproduce:

• Open up the Python scripting window and place it in a position similar to that shown in the attached image.
• Set the Python window to be "Always on Top".
• Type "Load" and press enter into the Algorithm field as shown in the image.

The ​modal nature of the dialog means that you can't click outside of the dialog, but the Python scripting window will block you from clicking on the dialog!

Use Alt+F4 to close the dialog and regain control of Mantid.

I've set this to minor since this will probably be quite a rare occurrence.

[Nick Draper]

bulk move to assigned at the into of the triage step

[Stuart Campbell]

This ticket has been transferred to github issue ​9312