* 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
Non-select filter labels and their contents were misaligned. They were also shorter with lighter hover backgrounds. Everything should match up now. There's only one currently, but I used general selectors which should work in case any new ones are added.
Manage: Disable tabindex in nested buttons
Manage: Fix homepage link alignment
Manage: Make entry actions keyboard navigatable
Manage: Add search help accessibility
Msgbox: Save and restore focus
Manage: Fix delete confirmation cancel
Manage: Make history button accessible
Manage: Make favicons dropdown accessible
Manage: Prevent focus on hidden textarea
Msgbox: Stop tabbing outside of msgbox
Usercss: Make nondefault reset accessible
Usercss: Make colorpicker accessible
Edit: Disable tabindex in nested buttons
Edit: Make info and config icons accessible
Options: Cleanup HTML
Options: Make advanced toggle accessible
Edit: Fix issues popup
Edit: Remove link underlines from icons
* same icon in manager
(didn't change the editor config icons as those aren't for usercss)
* "external" icon for USO styles to avoid confusion
(opening a tab is an extremely different action)
* smaller paddings in popup
* removed hover effect on label text
(necause native <select> elements cannot be expanded from js)
* various fixups
