Guards! Guards!

Now you know where they are! A line that does not loop on itself means
that they do a 180 and go back.

Cops always spawn. Only some of the ghosts spawn.
UI

Everything is in the folder "UI Scene".
The bar is ghosts killed.
The hearts are health. When there are no more hearts, you die! And there
is a die screen.

There is a restart button that basically doesn't work because there is
no way to restart.
merged gardner branch into master.