Zoom/Unzoom feature as single click

[SamuelLongchamps]

Rather than having a magnifying glass as a tool, it would be a lot more intuitive to have the zoom/unzoom feature as a button instead. This is a lot more common nowadays and a scrolling bar for the zoom would be again very useful (think MS Office-like).

Another useful feature while working on this would be a 1:1 button which would fit the page into the screen fully and set 100% zoom. This should be located on the top bar, but not too close to erase to prevent any misstep.