Dexie v1.3.6-beta.3

Quality assurance:

• Run eslint on all code and enforce eslint passing in release script
• Launch unit tests on browserstack d9228dc in release script. Currently just Chrome, Firefox and Edge. Will add more devices and browsers later.
• Code review and some actions taken b29ec59:
  • Separating extend() into extendProto() and extend() (different use cases).
  • db-classes (Collection, Table etc) now have non-enumerable methods now on their prototype.
  • New method dump() on errors derived from DexieError. Returns string. To be used instead of (e.stack || e). It will dump name, message and stack. Like 'stack' on chrome but also for Firefox.
  • Static method Dexie.dump(error). Works as DexieError.dump().
  • Promise default uncaught handler: console.warn() instead of console.error().
  • Typescript definitions updates.