Improve handling of changes to workspaces while Dialog box is visible

[Nick Draper]

Now that dialog boxes are non modal you can have the underlying workspaces change while it is visible (you could before, but now it is more likely).

e.g.

1. Open Rebin
2. Load a workspace
3. try to select that workspace in the rebin dialog - not possible

The workspace lists need to work more dynamically with the ADS and at least refresh when the Run button fails.

This may be better done by replacing the controls with mantid widgets.

[Nick Draper]

Moved to the backlog at the code freeze of R3.3

[Stuart Campbell]

This ticket has been transferred to github issue ​10635