Add directory type watching folders for new style sheet files
Reimplement StyleEngines dir watcher with StylesDirWatcher
Publish StylesDirWatcher to QML

... and deprecate the former functions in StyleEngine.
Change API to use url based accessors

... and deprecate the stylePath/styleName approach.
Add style change menu to example app
Add example file for a version 1.1 StylesDirWatcher
Update and improve documentation