Listen to the new project changed event from the VM and keep track of the state in Redux.  Update it as appropriate.

Known issue is that the project is marked as "changed" immediately after it's loaded. This is due to asynchronous event emitting while the project data is loaded, and needs an update to the VM to fix.

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

stripped title handling from sb file uploader
updated more projectState related names
simplified hash-parser-hoc logic slightly

changed componentWillReceiveProps to componentDidUpdate in project-fetcher-hoc and project-metadata-hoc

everything in new project lifecycle works, except when old project was also default one, then it loads new project twice

load new project, both json and title; set title on file load; draft of code to fetch title from api

styling for title field; correct input target in tests; make download filename safer with default, max length; in playground index, correctly pass props through to gui container

Just use ProjectLoaderHOC to translate props to redux. Trying to be clever about using both props and redux state together was... not clever.

Resolves #3040

Only call updateProject to load the project if there is a project id, or it’s the default project id.

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.

Update project-loader to look for project id as prop (i.e. from www), and fall back to hash.

- 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)