Fix *.twee with CRLF import

###### Version 1.8.3
* Fix extension's modal dialogs break some app's dialogs (namely, 'Formats')

fix .twee import doesn't correctly read story settings

Version 1.8.1
* Fix tags list isn't always up to date in tag color management window.
* Provide a dropdown with allowed color names (Chrome only)

* Support for SugarCube 2's media passages.
* Advanced tags colors management: use any number of colors!
* Now works on both http and https domains.

This version brings much better import and snippet insertion control, as well as improved customization

* Hotkeys now can be customized by user
* "Extension settings" button added
* All options changes are applied on-the-fly, without page reloading
* [Twee 3 spec](https://github.com/iftechfoundation/twine-specs/blob/master/twee-3-specification.md) compatible import/export
* Snippet insertion now gives granular control over merge/override passages, story meta, style and script
* *.twee import dialogue now allows user to decide what to do when story with the same name exists: backup old story, completely overwrite it or merge with granular control

Firefox compatibility