#408 feedback when nothing is selected

[Alison Eyth]

On each of your GUIs (including the analysis
configuration), if the user selects something and the
user needs to make a selection in order for the software
to do something, please notify the user of that. So, we
should have no buttons that do nothing when clicked -
either they take an action, or notify the user of what
needs to be done in order for an action to be taken.

This also applies to the recent files menu item when
there are no files available in the list.