The goal is to support texts as native objects in
LayoutToNetlist.
Primarily this means, that instead of using a Region
to identify a layer, it is encouraged to use a
layer index instead. Also, Region is not longer the
only way to represent a layer, Texts is available
too.
It is possible now to retrieve the texts of a net
using "texts_of_net".
Also, the "lmap" parameter of "build_nets" became
optional. If "nil", a layer map is created based
on the layer info attribute of the layers.
Matthias Koefferlein