Zoom to point slightly off in FF (win)

[computermacgyver]

Very happy that I implemented zoom to point (e.g. zoom in where the cursor is when using the scroll wheel). This works fine in Chrome, but is just slightly off in Firefox. Note to self to investigate (and test!) further.

[computermacgyver]

Regression: Zoom to point is slightly off in Chrome as well after implementing features to center map vertically on load