27 Mar 2013: 0.0.5 "c++" release for OpenEMS v0.0.30
 - Joins adjacent and overlapping copper
 - pdf output added

29 July 2013: 0.0.6 release for OpenEMS v0.0.31
13 September 2013: 0.0.7 release
 - bug fixes.
 - attempt at PLANE type polygons and PLANE layers.
   These are polygons and layers which are flooded with copper, 
   where the copper automatically keeps a preset clearance between nets.

1 March 2014:
 - allow for lossy copper and lossy dielectric

21 February 2015:
 - adapt for bison 3
 - add board outline if board outline is not defined
 - allow blind and buried vias

29 April 2015:
 - add option for 3d metal
 - fix stack height