WebStory Engine 2017.1.1

This is a bugfix release for 2017.1. If you use that version, you should probably update.

Here's what changed:

• Fix italic text (issue #28)
• Fix shake effect (issue #29)
• yes and true are now both considered truthy attribute values and can be used interchangeably
• Fix wrong attribute values in audio tests

This is also the first release to ship with the documentation included in HTML format!