Make buildDirectoryInitialized a Qt4Project specific signal again

And fix it to the old behaviour while at it.

Change-Id: Ifd786e085c621fb3cd59b98cc665d9e3c7fcce51
Reviewed-by: Tobias Hunger <tobias.hunger@nokia.com>

src/plugins/qt4projectmanager/qt4project.cpp

@@ -1543,6 +1543,10 @@ void Qt4Project::collectLibraryData(const Qt4ProFileNode *node, DeploymentData &
     }
 }
 
+void Qt4Project::emitBuildDirectoryInitialized()
+{
+    emit buildDirectoryInitialized();
+}
 } // namespace Qt4ProjectManager
 
 #include "qt4project.moc"