pcb-rnd 2.4.0
~~~~~~~~~~~~~

This release is a major cleanup release, the final preparation for a major
version change to 3.0.0 in the near future. As such, it finally replaces the
old, diameter based via description in route styles (and tools) with padstack
prototypes and introduces lihata v8 to be able to represent this change in
the native file format. It also has major code refactoring under the hood,
especially in export options API.

Feature highlight:

1. Route style switched over from 2-diameters via geometry to padstack
   prototypes. Video tutorials about this change:
   https://archive.org/details/pcb-rnd-via_pstk1
   https://archive.org/details/pcb-rnd-octa-via

2. Route style can remember and set text font to use

3. New file format versions: lihata board v8 and lihata subcircuit v8;
   new board version for the route style upgrades and more detailed
   text object clearance; new subc version for more detailed text object
   clearance.

4. Removed the half-working, export-plugin-specific printer calibration code
   in favor of a simpler, documented method the user can perform with any
   export flow.

5. New alien file format: load PADS ASCII boards with the io_pads plugin.