Clean headers in Utils.

Forward-declare QGraphicsOpacityEffect in DetailsButton,
QProcessEnvironment in Environment, QFileInfo in fileutils,
QUrl in IWelcomePage, FancyLineEdit in PathChooser and
remove unneeded headers.

Change-Id: I7d5f273530dd2059bbdaf0899f0a3bc7e49e8482
Reviewed-by: hjk <hjk121@nokiamail.com>

src/libs/utils/consoleprocess_unix.cpp

@@ -29,14 +29,11 @@
 
 #include "consoleprocess_p.h"
 
-#include "environment.h"
 #include "qtcprocess.h"
 
 #include <utils/hostosinfo.h>
 
 #include <QCoreApplication>
-#include <QDir>
-#include <QSettings>
 #include <QTimer>
 
 #include <sys/stat.h>