merged cells broken

in the middle of changing the detection of merged cells. its completely broken, but commented out so everything still works
excelError loads PHP Exceptions

excelError can load a PHP exception. This allows the exception object to gather information about the trace, file, line, and pass it to the excelError object that know how to throw an error in JSON that can be caught be the UI
error throws added

error throws added to excelWorkbook private functions
static error throws

excelError: added static function to throw errors in a single call. Esp. useful when passing it an Exception as the argument.
header output function

sendOutput added to encapsulate code for writing the response header
private var name change

changed the name of some private member variables
doc comment added
ods support added

now successfully loads open document spreadsheet formats
ods support added

now successfully loads open document spreadsheet formats