qmlproject ignores run environment

1. Open examples/quick/demos/samegame/samegame.qmlproject from qtdeclarative in Qt Creator

2. add the environment variable QSG_VISUALIZE=overdraw.

3. Start the application in normal mode. Notice that overdrawing doesn't happen.

4. Start the application in debug mode and notice that the overdraw variable does take effect and a 3d representation of the scene is overlaid on top of the application.

Environment variables should be passed to the application, no matter what run mode is chosen.

The same also happens with other environment variables, most notably LD_LIBRARY_PATH, which gives more severe problems, but is not as easily reproducible.