simplified exception catching

The function catchExceptionToJSON can now catch and evaluate an error and return a JSON string. This simplifies error catching for pages that have to determine how to report the error back to the UI
excelFilePath returned to UI

Added the ability for the server to return the excelFilePath to the UI. Not sure if this is needed yet, but added it just in case.
simple UI update

simple changes made to the UI that better reflect the state it is in
jquery ui added