Add ember-cli-dependency-checker to app's package.json
Merge pull request #2454 from quaertym/master

Add ember-cli-dependency-checker to app's package.json
Update LICENSE.md
first pass at debug logging
use master of broccoli-sane-watcher to enable watchman support
force watchman on for now (until it is auto-detected by
broccoli-sane-watcher or sane)
allow GH deps
enable async watcher creation
using async watcher init, try and use watchman, or fallback to node if not.