cosmetics; channel renamed fron DataDesc to datadesc (should all be lowercase); make...

cosmetics; channel renamed fron DataDesc to datadesc (should all be lowercase); make gras_ddt_freev visible from ddt_parse; add gras_datadesc_declare_{struct,union}_close; fix an old bug remaining from GS (about fixed size array alignment); move gras_datadesc_parse() to ddt_parse.c

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/simgrid/simgrid/trunk@248 48e7efb5-ca39-0410-a469-dd3cf9ba447f