Build fix for tools

We have to check for Qt Versions and private headers to build qmlpuppet.

Reviewed-by: Kai Koehne

src/tools/tools.pro

@@ -2,9 +2,16 @@ TEMPLATE = subdirs
 
 win32:SUBDIRS = qtcdebugger
 SUBDIRS += qtpromaker
-SUBDIRS = qmlpuppet
 
 QT_BREAKPAD_ROOT_PATH = $$(QT_BREAKPAD_ROOT_PATH)
 !isEmpty(QT_BREAKPAD_ROOT_PATH) {
     SUBDIRS += qtcrashhandler
 }
+
+include(../../qtcreator.pri)
+include(../private_headers.pri)
+exists($${QT_PRIVATE_HEADERS}/QtDeclarative/private/qdeclarativecontext_p.h) {
+    minQtVersion(4, 7, 1) {
+        SUBDIRS += qmlpuppet
+    }
+}