Merge pull request #551 from janestreet/master

minor release of the core package
opa-base: using ocamlfind from the PATH
initial add of the riak-ocaml-client
Merge pull request #552 from metadave/master

Initial add of the riak-ocaml-client
add jenga and its missing dependencies
Merge pull request #553 from janestreet/jenga

add jenga and its missing dependencies
Add package for the newest version of Why3
Merge pull request #555 from protz/my

Add package for the newest version of Why3
cairo: make lablgtk an optional dep
websocket: add missing ssl dependency
Merge pull request #556 from pveber/cairo-lablgtk-option

cairo: make lablgtk an optional dep
Merge pull request #558 from mirage/master

fix websocket
batteries 2.0.0 doesn't compile on ocaml 4.01.0dev+trunk
atdgen.1.2.3 requires an as-yet unreleased atd (with the Nullable ast_expr), so add constraint
Merge pull request #559 from mirage/master

fixes to batteries/atdgen