Centralise grid size
Create some more rando islands
Draw most things as rects from inside Coquette

* Things can still have their own draw() if they want
Add u.vAdd() to add two vectors
Start mary more centrally
Move Mary() into own file
Speed up land movement
Rm diag movement, move in dir based on last key pressed

* Horrid code.
Put piece of food on every island
Rip out all fancy coll det stuff - just check rects
Bring back impassable trees