Issue I478 [GUI,mm-per-gu,enhancement,mostlyresolved] Reduce minimum PA mm/gu scaling from 1E-5 to 1E-6. Note: also precision of coordinates using "Where" function was increased. Note: min workbench size is still 1 mm^3 though (see Issue I513). Reported by mikhaily-20080211 Implemented in 8.0.5-TEST4.