Fix persistant bug report which is reproduced by undoing the addition of
a flight configuration.  Need to test if the current selection in the
flight configuration table is off the table's current size.
Fixed NPE reported through a bug report.  Somehow the listenerList was
null when a change event was fired.  Don't know how this really can
happen, but protecting against the NPE isn't a bad idea.
Fix reported bug.  The mass & cg override icons wouldn't appear
immediate when a components mass was overridden.  The ComponentTreeModel
needs to update the tree on mass changes too.
Update thrustcurves.
Merge pull request #209 from kruland2607/master

new thrustcurves and couple of bug fixes.