More Ember Testing

@ebryn @hjdivad @locks @shajith

 * git-ignore and fetch vendor dependencies instead of committing them
 * Ember 1.0 build uses 1.0.1, not RC3
 * tests can specify a Handlebars version (in addition to the jQuery and Ember versions)
 * Ember 1.0.1 tests use Handlebars 1.1.0
 * Add a test on (Ember canary, Handlebars 1.3.0, jQuery 1.11.0)