V0.1.0

I've been planning this for some time but had not the time to do it.

In v0.1.0, as exposed on some issues, will contain:

- [x] No more `console.log`
- [x] watcher for `gulp build` and `gulp hint`
- [ ] add a `prepareImage` method so that one can decode directly from an image
- [x] no more `setDecoderCallback` method
- [x] keep searching for new qrcodes by default
- [ ] expose a `once` argument for the `prepareVideo` and `prepareImage` methods
- [ ] add automated tests