Bugfixes

• Fix Block equality
  …
• Fix bug reading non-English projects

Thumbnails and bugfixes

Fix some vague things, and add some stuff in preparation for the Snap! plugin.

• Fix a bug opening new Scratch 2.0 files
• Fix a bug opening projects made with Kurt in Scratch 1.4

API changes:

• Project.thumbnail is now an Image, not a Costume. This is a mostly backwards-compatible change.

Scratch 2.0 support, All-new interface

• All-new interface
• Supports both Scratch 1.4 and 2.0
• Documentation hosted on Read the Docs