Fixed: Promise -> promise
Merge branch 'master' of github.com:theworkers/W.js

* 'master' of github.com:theworkers/W.js:
  Release v4.17.2
  Fix remove log
  Release v4.17.1
  Added: state checking and error events

Conflicts:
	build/W.min.js
Post merge build
Release v4.18.0