Clean headers in QmlJs.

Ran script to remove inludes on a trial-and-error basis and
manually corrected it (Parser excluded).

Change-Id: I5ec6e1076430009bb72094411b2c3386f8bea548
Reviewed-by: Aurindam Jana <aurindam.jana@digia.com>

src/libs/qmljs/jsoncheck.h

@@ -33,14 +33,11 @@
 #include "qmljs_global.h"
 
 #include <qmljs/qmljsdocument.h>
-#include <qmljs/parser/qmljsastfwd_p.h>
 #include <qmljs/parser/qmljsastvisitor_p.h>
 #include <qmljs/qmljsstaticanalysismessage.h>
 
 #include <utils/json.h>
 
-#include <QString>
-#include <QSet>
 #include <QStack>
 #include <QList>