Fix notes from AMO review

[ameshkov]

1) in preload.js you use:
setTimeout(function () {
   this.tryLoadCssAndScripts.bind(this);
}, 100);
which will not work. Aside from the this object being different in the inner function, you are not actually calling the bound function. This will work instead if you are ok with an ES6 version, otherwise I'm sure you'll know what to change.
setTimeout(() => this.tryLoadCssAndScripts(), 100);
You can also just use setTimeout(this.tryLoadCssAndScripts.bind(this), 100); the validator warning that shows up for that will usuall be ignored by reviewers, since they see that you are actually passing a function.

2) In resources/adguard-adblocker/lib/main.js, shouldn't that last line be __proto__ instead of __proto ? I guess this can also be cleaned up using Object.create(null) as mentioned previously.

3) I'm a little worried about the applyScripts method. I read you are injecting remote scripts only for non-Firefox, but I have to rummage through multiple levels of function calls to figure out if that is really the case. If you could add another check for isFirefoxBrowser closer to the applyScripts method, that would be super.

[ameshkov]

For now I'll disable ALL script rules except hard-coded in Firefox add-on.