Issue a warning when unsaved changes to Equipment would be discarded

[UrsKR]

From @curttasker in #332:

Minor issue that got missed in the refactoring

1. Open Equipment Database
2. Click on an item in the left hand pane
3. Make a change to the item in the right hand pane.
4. Click on a different item in the left hand pane.

Expected: A Warning dialog box pops up stating "You have unsaved changes. Discard them?"
Actual: Changes are discarded automatically, right hand pane is changed to reflect the newly selected item