Makefile tweaks and Nix{,OS} support

As it's in git.

On NixOS, /usr/bin/awk doesn't exist.

 * the corresponding database columns (seldom) contain the accenting character
   (see e.g. sresat')
 * as noted in the comments, always accenting the partner is not trivial

 * the schema didn't change
 * included a fix for "pered" which failed to format with the new DB
 * "saliwnij" and "paraf" still cause errors with `make check` since
   they are stored errounously accented in words.bare