Add multilingual support (multiple dictionaries)

[nightuser]

Initial implementation of multilingual spellchecking. Doesn't work on OS X yet, as I don't have any Macs right now.

[zcbenz]

👍

[zcbenz]

Sorry I just realized there is another huge PR #50 waiting there, I'm reseting the master branch and will revisit this PR later.

[anaisbetts]

I think that my PR breaks the concept of this one - @nightuser, what are you using multiple dictionary support for? Maybe I'm missing a scenario here

[nightuser]

@paulcbetts Well, I'm writing my thesis in Sublime because of similar multilingual support. It's mainly written in Russian, but has many English terms.

I don't think that it'd be hard to implement that in your version, as I've borrowed the idea from Chromium (it's supporting multilingual spellcheck since August). I'll look into your PR soon.

[nightuser]

@paulcbetts I've forgot to mention you in the original version of the post above. And I don't know whether notification has been sent to you.