Log message:
Update to 0.6.0. Fixes build.

28.10.2014 Release V0.6.0
  * added support for IP addresses in psl_is_cookie_domain_acceptable()
  * removed qsort_r() for compatibility
  * check for alloca.h before including
  * include effective_tld_names.dat of date 27.10.2014

Log message:
Import libpsl-0.5.1 as wip/libpsl.
Does not build on NetBSD due to use of unportable qsort_r.

A "public suffix" is a domain name under which Internet users can
directly register own names.

Browsers and other web clients can use it to

* avoid privacy-leaking "supercookies" avoid privacy-leaking
* "super domain" certificates (see post from Jeffry Walton) domain
* highlighting parts of the domain in a user interface sorting
* domain lists by site

Libpsl...

* has built-in PSL data for fast access
* allows to load PSL data from files
* checks if a given domain is a "public suffix"
* provides immediate cookie domain verification
* finds the longest public part of a given domain
* finds the shortest private part of a given domain works with
  international domains (UTF-8 and IDNA2008 Punycode)
* is thread-safe
* handles IDNA2008 UTS#46