Move js code in to a lib folder

Looks cleaner...
Pull keymaster out of lib folder

It's an external library so best to keep it separate from my code.
Remove debug console.log statement
Modify moving object

Previously we fed a velocity into moving object. Now Moving Object takes
a speed and direction and velocity is calculated from that.
Modify movement controls

Up/down now increase/decrease speed. Left/right now turn.
Improve turn controls

Hey, there's some linear algebra for that...
Alert with a better death message.
Improve bullet firing.

By changing how we track the ships direction, it is now possible to fire
bullets while stationary. Previously, we couldn't get a direction while
stationary.
Render the ship as a triangle

So that we know which way we're facing...
Add control instructions