Added a unit test and covered the other case (not used) where you might be trying to update the index zero of a list

This prevents a tutorial with no urlId being returned in the case of no tutorial query param

Nice catch @kchadha!

made remixing, saving as copy states; made project state naming more consistent

changed meaning of canCreateNew to true creation

fixed project-saver-hoc test

removed Remix option from standalone player menu; renamed canSaveAsCopy to canCreateCopy

added parenthesis missing from rebase

fixed create new test

responding to canSave without needing canSaveNew prop
removed canSaveNew
added default for onUpdateProjectId
removed conflict files erroneously added
don't pass down onError
got tests passing
better creating and saving logic and names

* Look up video id based on locale.
* add japanese video ids
* add test

This ensures that the reducer is actually called with the project data that storage loaded

Remove the default prop test because the default projectId prop comes from redux now, so it doesn't make sense to test the default

Lint

Locale detection function that checks browser setting and lets URL parameter (locale= or lang=) override the browser setting.

Add `?locale=<localecode>` to load in a new langage.
Add `?enable=language` to enable the language selector
Or combine the two: `?enable=language&locale=<localecode>`
Still accepts a hash, but requires that the hash be a sequence of digits.

Added new locales reducer to gui:
- initializes default  react-intl/localeData
- initializes default locale messages for all locales
- default locale is ‘en’ (can be overridden by URL)

Removed dependency on react-intl-redux, added ConnectedIntlProvider (uses correct locale messages from redux based on current locale)

- better split of hash-parser/project-loader unit tests.

The project loader that is exported with GUI just expects to be passed projectId as a prop, and it manages loading project data.

The part of the project loader that watches for URL hash changes for the playground is a new HOC that is only used in the various playground examples.

- export image and sounds in dist/static/assets
- rename main export (`scratch-gui.js`, not `index.js`)
- move project-loader-hoc back to lib (VM doesn’t load properly without it)

Allow intl to be passed in to GUI as a prop (rather than having to be already in the store)

/ht @paulkaplan

Previously we tested the ProjectLoader helper object, but now all loading is confined to storage. Unfortunately I wasn't able to get enzyme to wait for the storage promise to resolve within componentDidUpdate, so I can't test the actual results of storage.load, just what it was called with.

Add a setup file that configures the React adapter. Fix one deprecated usage for ProjectLoaderHOC tests.

There are some tests still broken, but these weren't called out by Enzyme.