/ht @paulkaplan

Use the de/serialization features of the VM to allow downloading and loading project JSON

It doesn't help anything. Doing a deep compare is unnecessary because the underlying components will do the necessary comparison themselves. Simply seeing if the sprite list has changed at all is enough.

With jscodeshift thank God

* Fix costume loading in sprite info pane

Requires LLK/scratch-vm#517

* Fix costume loading in costumes tab

Requires LLK/scratch-vm#517

Attaching the storage module in `vmListenerHOC` means it can propagate
down to the GUI, stage, and blocks naturally. The default VM property
value has been removed from those places so that we're not instantiating
extra VM instances any more. Instead, using one of those components
outside of the `vmListenerHOC` framework will require providing a VM
instance as a property.

Remove target pane button and actions

Add back putting the sound library in the ui

Fixes #156 + refactored classnames to style guide conventions

Affects SpriteSelector Pane, StageSelector Pane, Stage, MenuBar, Libraries Modal, Add/Import buttons, for Chrome, Ffx + Safari on Sierra.

Fixes #162

* Buffer sprite info text fields

Changes to the name, x, or y fields should only be sent to the VM when the field is blurred or when enter is pressed.

Still allow updates while the fields are focused, but unchanged.

Fixes #154

* Remove focus from input fields after hitting enter

* Fix prop types for info component and container

Refactored towards better convention for linting.