Log message:
Drop distinction between PKGSRC_USE_TOOLS and USE_TOOLS by making
PKGSRC_USE_TOOLS go away.  There is now only a single USE_TOOLS variable
that specifies all of the tools we need to build/run the package.

Log message:
Add RMD160 digests.

Log message:
Initial import of Jochen Kunz's documentation for writing device drivers
for NetBSD (written in German) into the NetBSD Packages Collection.

A "NetBSD Device Driver Writing Guide":

It consists of three main sections:

- Introduction to autoconfig(8).
- Usage of the autoconfig(8) infrastructure, demonstrated on the example
  of rf(4).
- Core of the rf(4) driver, that shows how data is transfered from and
  to a (disk) device.