Major fixes, API change

- Changing `this.watcher()` to be `cluster.Master` centric
- Updating `this.register()`
- Updating `this.unregister()`
- Made `this.watcher()` DRY
- Fixing `this.handler()` to only update LRU cache when Client is making a GET
- Updated `this.proxy()` to utilize only `this.respond()`
- Updated `this.request()` to only utilize `this.watch()` for LRU
- Added optional boolean to `this.request()` arguments to specify a local asset
- Fixes #126
- Fixes #139
- Updating docs