Bug 1039984 - [System] Trying to open a smartcollection after killing th...

...e Homescreen do nothing.

Allow Homescreen application window to be killed as other windows.
Either homescreenWindow has it kill method or appWindow check config to use different way to kill makes sense.
Though check this.isHomescreen in appWindow looks a little strange. I will figure out a better (use kill config instead of type of window)