Add phantomjs and mocha-phantomjs to dev dependancies
Remove old phantomjs reporter
Upgrade let script to use lazy()
Upgrade mocha to 1.17.1
Update Makefile to use mocha-phantomjs

Also now installs missing dependancies when run for the first time.
Add bind polyfil for use in Phantom
Update use of let() to use lazy()

Hopefully using the context object makes it clearer what is being
accessed and on what object.