update ember.js to rc3
update yui to 3.10.0

closes #566
Merge pull request #573 from Daniel-Hug/master

Add Handlebars to libs
Merge pull request #574 from fivetanley/update-emberjs-to-rc3

update ember.js to rc3
Merge pull request #575 from fivetanley/update-yui

update yui to 3.10.0
Move grunt into devDependencies.
Resolve custom config paths before loading the file.
Resolve config from cwd and document the JSBIN_CONFIG variable.
Merge pull request #578 from remy/fix/dev-dependencies

Move grunt into devDependencies, close #576
Merge pull request #579 from remy/fix/config-from-env

Resolve custom config paths before loading the file, close #577
Merge pull request #585 from Daniel-Hug/master

Fix double semicolon typo in CSS.
Prevent scroll even from embedded jsbin bubbling to outer page.
Merge pull request #591 from remy/fix/scrolling-embed-395

Prevent scroll event from embedded jsbin bubbling to outer page.
bump ver
Try moving cancel of focus event to earlier in code
Remove a ton of whitespace errors.
Don't autofocus the console if embedded.
Remove autofocus from console textarea.
Don't replace console. for window.top.console. when embedded.
Support CSS import from gist.