Complete design of Run Model dialog

The available hosts will need to be configured externally.
Disable autohide property on dialog boxes
Remove ListPanel widget

It's not used, and if I choose to use it later, it should be rewritten
to look more like DroplistPanel.
Trap browser reload/close events

Present a choice dialog to the user if the currently displayed model is
unsaved. Note that browser reload/close events are indistinguishable!
Give all text boxes a background color

And a secondary style.
Check for out-of-range and non-numeric parameter values

The ValueCell checks each character. If the user-entered value is
non-numeric or out-of-range, the ValueCell background color turns red.
Update "valid range" tooltip on parameter value
Add message that model must be saved before upload/run