v1.2.4

Fix

(#1404) Short Circuit resolvePaths if no Targets (bp #1392)
(#1411) [spec] clarify that div-by-zero is undefined (bp #1409)
(#1415) Update single-line when/else example in spec to match implementation (bp #1414)
(#1419) Fix error message for NegWidthException (bp #1418)
(#1425) Revert inline nots only 1.2.x (bp #1422). Fixes #1426
(#1423) Clone Verilator from GitHub, fix tag name
(#1431) Check sign of primop constants where appropriate (bp #1421)