Feature: ESM

[larslaade]

Hi,

here is my PR for jsb as an ES module. Fixes #37

• [x] Code uses import/export
• [x] Rollup as a Builder
• [x] Remove internal RequireJS support
• [x] Remove domready
• [x] Update test cases
• [x] Readme updated
• [x] Typescript type definitions

Breaking changes

• BREAKING: removed internal RequireJS-Support
• BREAKING: changed parameter order on the "on"-function
• BREAKING: removed applyBehaviour on the dom-ready-event