Merge from vendor branch TNF:

Merge from vendor branch TNF:
Import tex-arabi-1.1 from pkgsrc-wip.  Packaged by Kamel Derouiche.

The package provides the Arabic and Farsi script support for TeX without
the need of any external pre-processor. The bi- directional capability
supposes that the user has a TeX engine that knows the four primitives
\beginR, \endR, \beginL and \endL. That is the case in both the TeX--XeT
and e-TeX engines. Arabi will accept input in several 8-bit encodings,
including UTF-8. Arabi can make use of a wide variety of Arabic and
Farsi fonts; PDF files generated using Arabi may be searched, and text
may be copied from them and pasted elsewhere.