Create editor folder for all the editor components:
* blocks - from scratch-blocks
* extensions - from scratch-vm
* interface - from scratch-gui
* paint-editor - from scratch-paint.
Update the transifex config, initilaize with the english sources.
Export a combined editor-msgs.js in addition to individual files.
Renamed paint to paint-editor to match the name in transifex.
Breaking change - bumped major version to 2.
Restructured to support multiple components. Package default is just localeData for currently supported locales including the name for each language.
messages for each component are exported as separate files in locales. Clients of l10n will need to import messages for each of the compents used and combine them.
