v0.4.0

This release marks end of major API changes in what is probably close to a v1 release. Will stick to semver from now on.

Changes since v0.3.20:

• Improved dialog polyfill examples in demo pages

• Fixed bug with event payloads

• Shortened event name prefix to bm:

• Updated README with better compatibility info

• Added version number to demo pages

Full Changelog: v0.3.20...v0.4.0