* Implement Dropbox export (#82)
* Remove wrong dropbox api key
* Improve implementation of Dropbox by using identity.launchWebAuthFlow api and get rid of web_accessible_resources
* We don't need a dropbox receiver anymore, remove constante with the html file
* Implement compression in dropbox export
* Add LICENSE file from dropbox and zipjs
* Fix code style error
* Fix code style and folder structure of the feature
* Fix eslint error in dropbox implementation
* Add real dropbox api key from stylus dropbox account
* For test only: fixed addon's ID on firefox
* Change the file not found message to a better one
* Add dropdown style on export and import buttons
* Changes arrow from buttons to svg
* Remove applications entry on manifest.json
* Remove unnecessary break line
