Updated Jane Street's success story

putting more emphasis on JS's open-source libraries.
OCamlPro logo: cropped and made transparent
Add a few OCamlPro logos, and update commercial offer description
OCamlPro: reviewed the changes as per PR comments
Add a paper URL

The Essense of ML Type Inference
Merge pull request #337 from loverdos/papers_essense_of_ml

Add a paper URL
update next NYC OCaml Meetup event
fix wrong link to OCaml 2013 Meeting
Add a title to news headline links.
Fix the "Streams" tutorial so it displays.

All `tryocaml` were also changed to `ocamltop`.
Fixes https://github.com/ocaml/ocaml.org/issues/340
Remove all ```tryocaml

On the way mane code blocks were also corrected.
Fixes https://github.com/ocaml/ocaml.org/issues/282
docs/index: add link to List of Videos

Addresses #298.
docs/index: slightly move links to Books and Papers

I think it looks better here. Related to #298.
make links at bottom of each section in landing page more consistent

Related to #298. Each link is now enclosed in <footer>, uses similar
wording, and avoids custom font size.
Update 99problems.md

2 additional solutions for balanced trees
99problems: Add a link to easily find a helper function
Use more usual names for OCaml
Fix spelling.

Fixes https://github.com/ocaml/ocaml.org/issues/342
companies.md: minor grammar fix in Jane Street quote
Added Bloomberg Finance L.P. to the learn/companies.md