Merge pull request #5 from ArnaudParant/master

Included 4Store binding into ocaml-rdf
configure, compile and install rdf_lwt
add Rdf_json, use this module in Rdf_sparql_http_lwt; no more default /sparql/ at the end of uris used by Rdf_sparql_http_lwt.get
fix module name in Rdf_uri: Uriset and Urimap
compile implementation of sparql protocol; not tested yet
add missing files + first test of sparql protocol ok
ignore exes
improve handling result in xml format
send sparql queries with post
add documentation or sparq protocol modules
set headers + add missing files
update doc, fix META.in
fix doc source: elt->doc