[kepler-dev] Fixed long standing problems with spurious errors on command line

[Edward Lee]

I've checked in changes that eliminate a source of spurious command-line 
reports of errors
documented here: https://projects.ecoinformatics.org/ecoinfo/issues/6000

The errors result in output like what is below appearing on the command line
when copying and pasting variables.  This was a simple bug in the 
OffsetMoMLChangeRequest class.
We didn't see this bug before because the command-line was getting 
cluttered with other
spurious error outputs.

Edward

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: 
ptolemy.actor.parameters.LocationParameter cannot be cast to 
ptolemy.kernel.util.Location
     at 
ptolemy.vergil.basic.OffsetMoMLChangeRequest$1.run(OffsetMoMLChangeRequest.java:230)
     at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
     at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:715)
     at java.awt.EventQueue.access$400(EventQueue.java:82)
     at java.awt.EventQueue$2.run(EventQueue.java:676)
     at java.awt.EventQueue$2.run(EventQueue.java:674)
     at java.security.AccessController.doPrivileged(Native Method)
     at 
java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:86)
     at java.awt.EventQueue.dispatchEvent(EventQueue.java:685)
     at 
java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
     at 
java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
     at 
java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
     at 
java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
     at 
java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
     at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)