Better handling of implicit statement in source code browser

When using e.g. IMPLICIT INTEGER only the IMPLICIT was seen as keyword and INTEGER was not seen as keyword. Now types are seen as keywords as well.

src/fortrancode.l

@@ -795,7 +795,7 @@ PREFIX    (RECURSIVE{BS_}|IMPURE{BS_}|PURE{BS_}|ELEMENTAL{BS_}){0,3}(RECURSIVE|I
   					  codifyLines(yytext);
 					  endFontClass();
 					}
-<Start>"implicit"{BS}"none"             { 
+<Start>"implicit"{BS}("none"|{TYPE_SPEC})  { 
   					  startFontClass("keywordtype"); 
   					  codifyLines(yytext);
 					  endFontClass();