Log Message:
Import artha-1.0.3 as textproc/artha, provided by David H. Gutteridge
in PR 49953.

Artha is a free cross-platform English thesaurus that works completely
off-line and is based on WordNet. Artha is a handy thesaurus that
focuses on high usability, without trading off simplicity and ease of
use. It has the following distinct features that increases its
usability: hot key lookup, regular expressions search, notifications,
suggestions, relative to sense mapping.