[muparser] Remove muParserError.h

To help remove exception handling, we will need to have a type that
has visibility into both ParserError and value_type. We're going to
put this type in muParserDef.h. Remove the error header and fold its
contents into muParserDef.h.

muparser-2.2.5/include/muParserToken.h

@@ -33,7 +33,6 @@
 #include <vector>
 
 #include "muParserCallback.h"
-#include "muParserError.h"
 
 /** \file
     \brief This file contains the parser token definition.