!!!Directory structure for building proofing tools and their installers

* proofing lex files:
** top level: technology, e.g. polderland, hfst
** second level: language
** third level: tool - speller, hyph, etc
** fourth level: testing

* tools and their installers:
** top level: technology, e.g. polderland, hfst
** second level: host application, e.g. Off2004, InDesign CS3, ...
** third level: language
** fourth level: tool (speller, hyph) - do we need this?