Popup:
* Enforce 200-800px range for the popup width option
Manage:
* faster search via cachedStyles.byId
* faster restoration of search results on history nav
* style name is clickable and opens the editor
* animated highlight of style element on update/add/save
* expandable extra applies-to targets
* remember scroll position on normal history navigation
* boz-sizing in #header, also in editor
* applies-to targets use structured markup
* get*Tab*, enableStyle and deleteStyle are promisified