Fixed incorrect height for tag preview

It's hard to reproduce this bug, so it might not be correct. But morally it is, and some testing shows that it is okay.
Fixed tooltips and zoom

The solution was easy. If only I didn't waste my time on calculating the cursor's position from the translation / scaling information in SVG...
Implemented minimizing the controls screen
Merge branch 'new' of github.com:stacks/stacks-website into new
An imperfect way of handling dragging and panning

Because fast movements make the source to be the background, but not very often, this is a possible solution.
Merge branch 'new' of github.com:stacks/stacks-website into new
Improved the referencing tags on statistics page

It now shows the information I want to see on this page. I'm not claiming the layout is optimal.