Also include the hash of the project in load errors from the server so we can debug them

* Export initial states for each reducer
* combine all gui reducers (excludes scratchPaint and intl)
* combine all initial states to create default guiState for preloading in www
* expect all of the gui state to be accessible at `state.scratchGui`

It's a cleaner API IMO but ended up being a messy implementation...

These use a technique where the save/load functionality is passed from the component to its children via a function argument.  I opted for this rather than a higher order component because it is more readable and requires fewer intermediary components.

This could just as easily been done with a higher order component and would be happy to change it to that instead.

There is a performance implication since there is a function being defined in render. However the menu bar is not a highly re-rendered component, so I thought it would be ok in this case.

Revert "Changes to hash should happen through project loader hoc. Changes to the current project id and current project data should happen in a reducer since they are part of global state. That way, the load button can affect the global project data as well."

This reverts commit e4fe143b.

Changes to hash should happen through project loader hoc. Changes to the current project id and current project data should happen in a reducer since they are part of global state. That way, the load button can affect the global project data as well.

Load button file input should only accept specific file extensions. Update load button to use new revamped loadProject function from VM. Loading a project via load button should clear the url hash (without triggering a reload or the project-loader-hoc).

Removing JSZip dependency. VM will unpack the zip (for now, until this functionality gets moved to scratch-storage).

This use of shouldComponentUpdate is wrapping the incorrect use of bind
in the mapStateToProps call.

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