OCamlPro logo: cropped and made transparent
Add a few OCamlPro logos, and update commercial offer description
OCamlPro: reviewed the changes as per PR comments
Merge pull request #316 from AltGr/ocamlpro-visibility

Following our discussion, improving OCamlPro's visibility a little bit.
replace ``foo'' by “foo”
2 list items wrongly caught in a code block
pull out list items from code blocks
remove double HRs
Use again jquery — required by the collapsed menu
Make the collapsed menu button work

Fixes https://github.com/ocaml/ocaml.org/issues/353
write OCaml Labs as two words

@avsm confirmed it should not be written as one word.