v3.3.0

Features:

• Updated documentation for AbortController to recommend a polyfill which is spec-compliant and fully synchronous. -- #814

Bug fixes:

• Fixed the "self is not defined" error that was reported for NodeJS applications - #794

• Reverted the DOMException handling refactor as the original code fixed issues in old Android browsers - #797

• Response.arrayBuffer() now always resolve with a ArrayBuffer as per the specification. -- #816

• Request and Response can now only be called via new (as constructors) as per the specification. -- #796

• Headers which are passed as a Headers object no longer have their names normalised as per the specification -- #798

Refactor:

• Removed the top-level this to stop warnings being emitted from Rollup. -- #815