Add a Tokenizer API.

This adds a `tokenize(code, options)` function to the exported object.

It uses the same API as when `options.tokens` is set.

It also uses Tim Disney's algorithm documented here:
https://github.com/mozilla/sweet.js/wiki/design

http://code.google.com/p/esprima/issues/detail?id=398
Editing autocomplete demo.

This is using Eclipse Orion editing component with the Content Assist
module from Scripted Editor.

https://code.google.com/p/esprima/issues/detail?id=400
Import and use Escodegen 0.0.18-dev.

https://code.google.com/p/esprima/issues/detail?id=401
Source rewriter demo: preserve comments.

https://code.google.com/p/esprima/issues/detail?id=402
Source rewriter demo: use Eclipse Orion as the editor.

https://code.google.com/p/esprima/issues/detail?id=402
Source rewriter demo: use a customized editor.

Also, share the custom editor setup with other demos. While at that,
group the common styles as well.

https://code.google.com/p/esprima/issues/detail?id=402
Validator demo: use Eclipse Orion as the editor.

https://code.google.com/p/esprima/issues/detail?id=403
Validator demo: display an errors with an indicator in the editor gutter.

Using Orion annotation feature, we create a warning annotation for every
syntax problem during parsing. Doing a mouse over on the annotation sign
will show the complete error description.

https://code.google.com/p/esprima/issues/detail?id=403
Validator demo: subtle color for the editor tooltip.

https://code.google.com/p/esprima/issues/detail?id=403
Validator and source rewrite demo: visual tweaks.

Avoid using pre's element cols/rows as it causes weird appearance with
Firefox.

https://code.google.com/p/esprima/issues/detail?id=402
https://code.google.com/p/esprima/issues/detail?id=403
Minify demo: use Eclipse Orion editor.

https://code.google.com/p/esprima/issues/detail?id=337
Import Esmangle version 0.0.10-dev.

https://code.google.com/p/esprima/issues/detail?id=337
Minify demo: use Esmangle to compress further.

https://code.google.com/p/esprima/issues/detail?id=337
Minify demo: make variable shortening (mangling) optional.

https://code.google.com/p/esprima/issues/detail?id=337
Minify demo: customize mangling pipelines.

Not every pipeline is customizeable at the moment, we pick some simple
optimizers first. By default, all possible Esmangle pipeline will be
used, some of them will be excluded depending on the checkboxes.

https://code.google.com/p/esprima/issues/detail?id=337
Revamp the site.

* Use Foundation 3 for a better look and typography
* Use Orion editor everywhere
* Add useful description to every example

https://code.google.com/p/esprima/issues/detail?id=404
Parser demo: use sm-treeview for the syntax visualization.

For a better performance and an improved look, drop the old TreeView
and use sm-treeview.

https://code.google.com/p/esprima/issues/detail?id=404
Fix the link to the syntax validator demo.

https://code.google.com/p/esprima/issues/detail?id=404
Add the link to Travis CI build page.

https://code.google.com/p/esprima/issues/detail?id=404
Add a list of all available demos.

https://code.google.com/p/esprima/issues/detail?id=404