update preprocessor

Not very nice right now, but the header had changed slightly. don't know if it works now, but at least it builds.

relast2uml.base/src/main/jastadd/scanner/Header.flex

@@ -13,5 +13,8 @@ import org.jastadd.relast2uml.parser.Relast2UmlParser.Terminals;
 %yylexthrow beaver.Scanner.Exception
 %scanerror Relast2UmlScanner.ScannerError
 
+%x COMMENT
+%s DECLARATION
+
 %line
 %column