Sketcher: Ignore small mouse moves after selection.
Switch to drag mode only after cursor moved 3 pixels.
Fix automatic creation of tangent constriants.
a. Use scale to calculate max distance
b. Consider only circle/arc that actually touch the newly created line
c. Use of arc angles correctly
d. Find nearest touch point (not nearest center)
e. some optimization
issue #1701 removed further except: statements
use exceptions in OpenSCAD module
try to use Execptions in Draft module