Use normalized and resolved `this.root` for watching and traversing rather than `dir`.
This was causing a nasty bug where on windows we have an entry in the `dirRegistery` `.` and the dir we're watching and binding `normalizeChange` on is the unnormalized passed in `dir` `./`.
Which caused the the dreaded `TypeError: Object.keys called on non-object` error. Fixes #26 #18 #16