Smooth tool bar hiding

[bogdan-the-great]

Is your feature request related to a problem? Please describe.
It's not. But maybe could be a fix for #622.

Describe the solution you'd like
Like in pretty much every other mobile browser out there, I want the tool bar to smoothly go up when scrolling down instead of it disappearing. I really like this smoothness that it provides in other browsers, even on older systems (downloaded Lightning browser on Android 4.4.2 and it looked smooth as hell there too).

Describe alternatives you've considered
None, I really think that there should be an option for it not if being a default. Lightning browser even had this, and it seems that at one point it was changed in here.

Additional context
Screen recording of this feature in Fulguris and SmartCookieWeb

[Slion]

There is an issue with the SCW, Lightning and even DDG implementation. They don't display the entire web page on the screen when the toolbar is shown. Instead the toolbar pushes the page outside the screen. That bug becomes even more annoying if you want an option to not hide the toolbar. You will never be able to scroll all the way down the page.

To fixed that I took another approach, which on some older devices might not feel as smooth but at least you can see the whole web page.

Worth noting that SCW does not hide the toolbar when you put it at the bottom.

It should be doable though to have this working even with the configuration flexibility that Fulguris offers. It's just way down the bottom of my priority list ATM.