Log Message:
Update textproc/nbsed to 20040821 (date of import from src HEAD).
Changes from the previous version include:

- Adding a sed2nbcompat script to ease importing from src HEAD into
  pkgsrc.

- Make this package depend on libnbcompat since it needs a regex
  implementation and it's also a bootstrap package.

* s/xmalloc/xrealloc/ so that large (greater than _POSIX2_LINE_MAX*2-1)
  multi line text can be added.