BAMF gets confused with StartupWMClass and multiple WM_CLASSes

Given a window with multiple WM_CLASSes, .desktop launchers will often trigger a notify event by binary match even if their StartupWMClass hint is not matched.

To reproduce, put the following .desktop launchers in ~/.local/share/applications:

    [Desktop Entry]
    Name=Foo
    Exec=gnome-terminal --disable-factory --class=FooWindow
    Type=Application
    StartupNotify=true
    StartupWMClass=FooWindow

    [Desktop Entry]
    Name=Bar
    Exec=gnome-terminal --disable-factory --class=BarWindow
    Type=Application
    StartupNotify=true
    StartupWMClass=BarWindow

Pin both to the Unity launcher, and click Foo to launch.

The desired effect is that only Foo launcher should pulsate. Currently, both Foo and Bar do.