add eliom-inc flag to eliomdep

eliom-inc has the same behavior of -I of ocamldep/eliomdep
but it prepend _server/_client (ELIOM_SERVER_DIR/ELIOM_CLIENT_DIR)
to the eliomdep's output for files which are into eliom-inc directories
distillery now use templates from template dir
Merge pull request #5 from shakurra/master

add eliom-inc flag to eliomdep