Convenient debabbling outside of browser

[yejingchen]

Currently babble'd text can be copied by simply clicking the copy bottun, then be pasted to other places. But debabbling can only work on web pages, by selecting elements containing babble'd text.

There can be a encrypt/decrypt switch on the addon dialog. When the switch is on 'encrypt', everything works as it is now; when it is on 'decrypt', do what 'debabble page elements' basically do.

Though it is not babble's primary use case to handle communications outside the browser, supporting that can also enable potential users to try it out (possibly on non-web IMs).

[kkuehlz]

I am willing to add this feature