pcb-rnd 2.2.1
~~~~~~~~~~~~~

This version is a feature release. On the infrastructural side the next big
step of the separation gets us closer to ringdove and the new drc_query plugin
gives a flexible frame for complex DRC implementations controlled by users.
On the feature side the most important new features are the
new import_sch code and bus extended object.


Feature highlight:

1. bus extended object: draw parallel buses (and differential pairs) as
   if they were single, thick lines

2. drc_query: query() language based, user programmable/scriptable DRC system
   plus a many upgrades to the query() functionality

3. import_sch rewrite: support any file format and input source instead of
   being specialized to gschem; replace the Makefile based input method with
   a generic "execute this command" method; give better control to the user
   about how new footprints are placed and footprints are removed by the import

4. librnd separation: librnd code is moved out from src/ to src/librnd so it
   will be easier to split off to a separate repository later

5. tool implementations (such as the line draw tool, via tool, etc) are moved
   out to the new tool_std plugin; this removes more GUI-only code from code
   but also allows new, advanced tools to be implemented in new tool_* plugins

6. configurable layer keys: the user can set the key binding for selecting
   or hiding/showing each layer; the key bindings are saved with the board
   as layer attribute

7. export code cleanup: decouple screen-visible effects such as selection or
   found color from export object color (this helps reproducible exports);
   refined okempty mechanism for CAM; provide a set of new layer supplements
   to CAM for drawing any layer e.g. in wireframe or with screen colors

8. the distalign plugin (distribute() and align() actions) now work on any
   object type, not only on subcircuits

9. relaxed drawing area limits: objects are not constrained to be within the
   drawing area and the cursor is willing to move outside of the drawing area
   by a wide margin

