Updated archetype FAQ

Dear all,

the archetype FAQ has been updated, to answer a very common question; see http://www.openehr.org/FAQs/t_archetypes_FAQ.htm#mozTocId539566.

New presentations are also available relating to legacy data conversion, and the ontological basis for openEHR modelling. See http://www.openehr.org/site_map/t_presentations.htm

- thomas beale