fix parser states and catch-all rule

src/main/jastadd/scanner/Keywords.flex

-<YYINITIAL,DECLARATION> {
+<YYINITIAL,COMMENT,DECLARATION> {
   "abstract"            { yybegin(DECLARATION); return sym(Terminals.ABSTRACT); }
   "rel"                 { yybegin(DECLARATION); return sym(Terminals.RELATION); }
 }

src/main/jastadd/scanner/RulesPostamble.flex

-<YYINITIAL,DECLARATION> {
+<YYINITIAL,COMMENT,DECLARATION> {
   {ID}                  { yybegin(DECLARATION); return sym(Terminals.ID); }
-  [^]                   { throw new ScannerError((yyline+1) +"," + (yycolumn+1) + ": Illegal character <"+yytext()+">"); }
 }
-<YYINITIAL,DECLARATION,COMMENT> {
+<YYINITIAL,COMMENT,DECLARATION> {
   <<EOF>>               { return sym(Terminals.EOF); }
-}
+  [^]                   { throw new ScannerError((yyline+1) +"," + (yycolumn+1) + ": Illegal character <"+yytext()+">"); }
+}
\ No newline at end of file

src/main/jastadd/scanner/Symbols.flex

-<YYINITIAL,DECLARATION> {
+<YYINITIAL,COMMENT,DECLARATION> {
   ";"                   { yybegin(COMMENT);     return sym(Terminals.SCOL); }
   ":"                   { yybegin(DECLARATION); return sym(Terminals.COL); }
   "::="                 { yybegin(DECLARATION); return sym(Terminals.ASSIGN); }