Many new things

Like:
* Tap on notifications to hide them
* Actually lock the screen by introducing a mousearea to lockscreen
* Notifications appear above statusbar
* Power button locking brings the lockscreen on top as it should
* Phone calls no longer linger in the background but are handled in a special layer instead
* Preliminary folder content showing
* Window close button is at a better place
* Sim panel hides when pin is entered correctly
* When a call is received, the alarm window should be swipeable away