COFC overview edge buffer changed to 1/6th of height
Tiltzoom changed to get angle relative to fixed ground
Camera zoom centering drift adjusts for target height
Initial overhead view now works for engine 98
Merge branch 'master' into cofc_tiltzoom_monotonicity
Zoomout and scroll fixes

* Zoom out from cursor stops properly at max y
* Scroll fixed to not correct zoomtilt angle unless zoomtilt is on
Fix zoom out from center zoomtilt angles
Merge pull request #320 from dvr333/cofc_tiltzoom_monotonicity

COFC zoom polish