Added implementation of mergesort in js
Completed an html5 cavas js game tutorial http://html5gamedev.samlancashire.com/making-a-simple-html5-canvas-game-part-4-adding-a-counter/
added w6d1 notes and exercises, foudation of asteroids project
working first phase of asteroids - displays all asteroids on the screen
asteroids render and move
asteroids have been wrapped in the canvas - if they disappear on one side, they reappear on the opposite side with the same velocity
find and handle collisions