[DAS2] DAS/2 retrieval spec docs

[Helt,Gregg]

Location of DAS/2 get HTML docs:
In the cvs.biodas.org repository
(http://code.open-bio.org/cgi/viewcvs.cgi/das/das2/?cvsroot=biodas)
 
HTML:
das2_protocol.html
das2_get.html
Schema:
            draft3/*.rnc