Replace tabId with windowId

[vhfmag]

This PR follows @Mathnerd314's suggestion to solve the too frequently shown "wait" state by replacing tabId with windowId in all browser.browserAction.setBadgeText and browser.browserAction.setTitle calls. I have tested this, but may not work properly in some edge cases, as I have close to no experience with WebExtension development.

Feedbacks are welcome and thanks for this extension!

Closes #24

[vhfmag]

For anyone following this, I have published this fork, that addresses #22 and #24, closing this PR and #25.

[Mathnerd314]

I've actually been using https://github.com/Loirooriol/tab-counter-plus since the day I filed #24. Just installing yours, it seems yours is still a bit slower to update than Oriol's, probably because it recounts the tabs on open/close so there's an extra IPC call.

Maintainership-wise, Oriol is also very fast to respond to issues / pulls, as opposed to the maintainer of this repo who seems to be busy painting graffiti and otherwise having fun at CMU. I don't want to say that you shouldn't continue your extension, but consider forking from Oriol's code instead of this one.

[vhfmag]

I wasn't familiar with Tab Counter Plus, thanking for pointing it out.

I'd just like to express that whatever this projects' maintainer is doing with their life is none of my business and if graffiti is what they'd rather be doing, so be it. That's one of the points of OSS: one can always fork unmaintained projects and move them forward.

Thanks for your valuable contribution and previously spent time, @DaAwesomeP!