Qmake: Re-parse project after changing the build directory

That is necessary so that the executables get updated.

Task-number: QTCREATORBUG-10107
Change-Id: I42e3ce38a5824e285546c43a3ec0045b090c6af5
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/plugins/qt4projectmanager/qt4buildconfiguration.cpp

@@ -234,10 +234,13 @@ bool Qt4BuildConfiguration::isShadowBuild() const
 
 void Qt4BuildConfiguration::setBuildDirectory(const FileName &directory)
 {
+    if (directory == buildDirectory())
+        return;
     BuildConfiguration::setBuildDirectory(directory);
     QTC_CHECK(supportsShadowBuilds()
               || (!supportsShadowBuilds()
                   && buildDirectory().toString() == target()->project()->projectDirectory()));
+    emitProFileEvaluateNeeded();
 }
 
 QString Qt4BuildConfiguration::makefile() const