defining the terrarium

Conflicts:
	terrarium.js
points in space

Conflicts:
	terrarium.js
representing the grid

Conflicts:
	terrarium.js
representing the grid - higher order functions

Conflicts:
	terrarium.js
a bug's programming interface

Conflicts:
	terrarium.js
the terrarium object

Conflicts:
	terrarium.js
animating life

Conflicts:
	terrarium.js
it moves

Conflicts:
	terrarium.js