Fixed recursive array comparison.

Fixes #816

Fix the sinatra example w/ #javascript_include_tag

The example was calling the sprockets asset without debug mode enabled.

fixes #1031

Since we have custom stuff to do around a script tag when using
sprockets let’s just mimic rails...

Don’t let updated dependencies break the examples.

Improve the usage section of the readme

- removed some outdated info
- fixed some syntax
- added instruction on how to interact with an ...

Keep guides in the repo

- Switched from raw tags to `NOTE:` mark for callout paragraphs
- Normalized titles to just use ...

This should help keeping them in sync with the repo and also allow
generating docs for differen...

ht @bbatsov

The opal/docs repo will be in charge of the docs generation.

Implemented nil#to_c, nil#to_r, nil#rationalize.

Correct earlier duplication of RubySpec for class descendants issue

Fix class descendant issue

* If we're equal, return false right off the bat

Optimize Enumerable#sort_by

I ran a benchmark that sorts a shuffled array of 50k objects. That
benchmark ran in 1040-1100ms ...

They're tightly coupled anyway.

It's not really the same thing, but it works for ASCII, it will need to
be added for real in Enc...

Closes #996

Closes #697