This removes the remaining hard-coded segments counts and replaces them
with the relative error calculation where the segments per arc is
determined by the maximum error we allow (smaller arcs = fewer segments)
Fix minor 3D viewer issues (includling change number of segments and its optimization to draw pad holes.)
Fix Bug #1439132 (track and via list on toolbar not always refresh after loading a board).
Remove useless tool in Modedit.
Seth Hillbrand
jean-pierre charras
Tomasz Włostowski
Simon Richter
Maciej Suminski
Wayne Stambaugh