pcb-rnd 2.2.0
~~~~~~~~~~~~~

This version of pcb-rnd is mainly a cleanup/bugfix version with 3
notable new features. One of the new features is the extended object
infrastructure, that provides a sustainable way to extend pcb-rnd features
with new tools and objects without having to complicate the data model.

With this release the second digit of the version bumped because pcb-rnd
is entering a new era. librnd (including the hidlib) is already installed
and being used by external applications. The new 2.2.x era is about
starting to separate librnd from pcb-rnd. This effort will take multiple
development cycles.

Feature highlight:

1. extended objects (line-of-vias and dimension lines)

2. OpenEMS export: suitable for microwave filter and antenna simulation

3. STL export: yet another path to 3D

4. io_eagle: various bugfixes and improvements in the loader allows more
   eagle boards to be loaded with less glitches

5. scripting: action code upgrade allows delivering the hidlib/PCB pointer
   to actions as argument (in argv[0]) which long term makes the code
   reentrant; centralized and unified layer and layer group addressing
   (using the syntax and experiences from cam)

6. windows port: the cross compilation setup got smoother and the startup code
   more robust, removing all known windows-port-specific bugs - locales and
   parametric footprint dialog work well now

