trust levels now default to a mid-level, with the password
modals explicitly tested for by the Context logic (the idea
being to deny any untrusted canvases the ability to render
inverted text).
ball bounce app also basically works, and context
switching between the bounce app and the main menu
is working too.
The first "app" is just going to be a whole-framebuffer
demo that gets raw keys and does some stuff on the screen.
It's the starting point if you wanted to eg. write a simple
video game or something for the device, but you didn't care
about much of the other UX sugar.
