pcb-rnd 2.1.0
~~~~~~~~~~~~~

The main focus was introducing mech/doc/misc layers and proper
slot support in padstacks.

New feature highlights:

1. layer model upgrade: mechanical layers for boundary and cuts and slots;
   remove layer stack assumption for a single outline layer

2. layer model upgrade: optional custom documentation layers

3. padstacks: support for plated and unplated slots of arbitrary shape

4. padstacks: hshadow (clearance around the hole, without copper)
   and UI support for "no shape" (no copper) thermal type for per layer control

5. arbitrary angle text rotation, option for user specified text line width

6. optional: user specified text object thickness, per text

7. ScaleBuffer() action that can resize (scale up/down) the buffer

8. trdraw: generic rendering transformations, such as object bloat/shrink
   while rendering for any output; accessible from the cam plugin

9. new dialog boxes: padstack browser with preview; undo dialog; fungw scripts

10. new io plugin: full board load from the DSN format

11. Major documentation extensions: resurrect action docs, add a lot of dev doc
