Merge pull request #1983 from NaterGator/qt-pch-compiletime

Precompile a handful of Qt headers to speed up compilation time

QGCApplication.pro

@@ -270,6 +270,12 @@ HEADERS += \
     src/MissionItem.h \
     src/AutoPilotPlugins/PX4/PX4AirframeLoader.h
 
+WindowsBuild {
+    PRECOMPILED_HEADER += src/stable_headers.h
+    HEADERS += src/stable_headers.h
+}
+
+
 !iOSBuild {
 HEADERS += \
     src/comm/SerialLink.h \

src/stable_headers.h

+#ifndef STABLE_HEADERS_H
+#define STABLE_HEADERS_H
+
+#include <QtCore>
+#include <QtGui>
+#include <QtWidgets>
+
+#endif // STABLE_HEADERS_H
+