[Kst] [Bug 85601] kst needs an "i'm busy" indicator

[Barth Netterfield]

Lets see if I can get the story correct:

At the end of [Data Wizard] we start doing something slow, which we keep track 
of with the progress bar.

The progress bar calls exec() on each progress bar update, which processes 
events.

The loading is slow.  While the loading is going on, the user does something 
(eg, deletes a vector which is being loaded, but which has not yet been made 
into a curve).  

Since exec() is being called, the event gets processed, which puts us into an 
inconsistent state.  BadThings(tm) happen.

Is this possible?  Is this what was causing trouble?