Questions:
* should the message strings include the number? Or should that get added to the name when the name is defined
* added a new ‘shared-messages’ to handle the definition of backdrop, costume, etc which are used in multiple places, they’re all related to defaults, so should it all be in `lib/default-project`

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

If the VM is ever instantiated, which happens whenever GUI is instantiated due to default props, then IE11 will crash

fixes #2983

- empty MapDispatchToProps (dispatch)
- remove `on…` VM listeners from props passed to wrapped component.

For some reason the travis eslint did not catch these missing prop validations.

*Kind of*. This isn't a good way to do it because we use the storage singleton before GUI is mounted. This needs to happen differently, like configuring storage in the project loader hoc and passing it down, so it could be attached to the VM once it has a VM?

Fixup 723d975d062ce3b585715b5cbabfcdae218d901a

This reverts commit 723d975d062ce3b585715b5cbabfcdae218d901a.

Also just cleaner formatting of the connect in the `errorBoundary` container

Don’t intialize cards position in reducer - position needs to be set based on isRtl.

Rename prev/next icons to right/left arrows

Make `NextPrevButtons` function RTL aware so that it puts the prev/next on the left or right based on the direction of the language.

* Delete confirmation i18n

* Update so that it works

* Don't show intro modal if hideIntro passed to PreviewModal

* Add hideIntro prop to GUI

* Move intro modal hiding logic into its own function