AutoTest: Clean up header mess

Better decoupling and reduced binary size.

Change-Id: I4f6239979d9d7dae4ad92f19ec8420be38372c07
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/autotest/testframeworkmanager.cpp

@@ -24,6 +24,7 @@
 ****************************************************************************/
 
 #include "testframeworkmanager.h"
+
 #include "autotestconstants.h"
 #include "autotestplugin.h"
 #include "itestsettings.h"
@@ -34,7 +35,6 @@
 
 #include <QSettings>
 
-using namespace Core;
 using namespace Utils;
 
 namespace Autotest {