With jscodeshift thank God

* Set editing target when double clicking on sprite in stage

* rename double clicker handler and add comment

* 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

There are a handful of places where the GUI code could use the storage
module directly; converting those is for a later change.

* 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

* WIP: drag states in stage component

* WIP: Hacky drag canvas

* Update sprite position on drag

Use VM to put sprite into drag state and update the sprite's position while dragging.

Temporarily don't use the drawable data to drag a new canvas, this can happen whne we have somewhere to drag the sprite to.

Refactor sprite info behavior into a container and let it handle the raw events.

TODO: refactor again into redux

Very crude, requires a refactor to allow toggling

For the time being, update the position onChange. Eventually this will update onBlur/on "enter" key

Resolves #16