Allow pausing and unpausing the game with P

I found out how to do it by looking at the code for the Pause button on every Phaser example.
Merge pull request #41 from roryokane/allow-pausing

Allow pausing and unpausing the game with P
Make main music play, with two-part loop

Phaser doesn’t support playing one sound immediately followed by another sound only when the first sound is finished, so I had to implement it myself.
refactoring: loseTheGame function; adding hotkeys
Added prototype spikes (no functions), chains

Chains no longer are affected by the world bounds while the bikes
are still stopped.
Merge branch 'gh-pages' of https://github.com/drexel-gmap-260-chain-gang/chained-escape into gh-pages

Conflicts:
	main.js
Add Mock ups of menu, instructions, game over screen

simple mock ups meant to demonstrate initial ideas
Use Aviva’s motorbike images for the players
Variations of the chain with 2 ideas

first idea, chain changes color as it weakens, from green to yellow to
red. 2nd idea, a dark color rust spreads as it weakens
Ver.2 of police motorbike just resized to fit others
Add Aviva’s road backgrounds to images folder
Merge branch 'gh-pages' of github.com:drexel-gmap-260-chain-gang/chained-escape
Reduce all image sizes using ImageOptim

Ran all images through ImageOptim  (http://imageoptim.com/) so the player has to wait less time for the assets to download.

Results: “Saved 2.9MB out of 6.1MB. 58.1% per file on average (up to 97.1%)”
Make white backgrounds transparent in obstacle images

The roadblock and spike images

I used Photoshop. I created a layer mask for the images that was the inverse of the images themselves, and then filled in any parts I wanted to be solid with white using the rectangle tool.
Move status text to a more out-of-the-way area
Added test spike object, changing roads
Merge branch 'gh-pages' of https://github.com/drexel-gmap-260-chain-gang/chained-escape into gh-pages

Conflicts:
	main.js
Add “You Lose” message when pressing L to lose
Give spikes their own vertical speed, defaulting to 3
Fix chain initialization location to be between players