Update esrefactor to rev 8ff2b6238b (Apr 15 2013).

https://code.google.com/p/esprima/issues/detail?id=414
Benchmark corpus: update jQuery Mobile to its latest version.

http://code.google.com/p/esprima/issues/detail?id=354
Benchmark corpus: use YUI latest version.

http://code.google.com/p/esprima/issues/detail?id=354
Add contribution guide in the form of CONTRIBUTING.md.

https://code.google.com/p/esprima/issues/detail?id=419
Update esrefactor to revision 34bc6e461e (Apr 21 2013).

https://code.google.com/p/esprima/issues/detail?id=420
Implement the rename refactoring demo.

https://code.google.com/p/esprima/issues/detail?id=420
Update esrefactor to revision c5081d5385 (Apr 23 2013).

https://code.google.com/p/esprima/issues/detail?id=420
Link the new rename refactoring demo.

https://code.google.com/p/esprima/issues/detail?id=420
Support `component`

http://code.google.com/p/esprima/issues/detail?id=342
Use the delegate to create the location information.

This is just the first step in that direction. Also, expect some
performance flakiness (it will be tuned again later).

It also brings the location annotation approach very much like the
original one proposed by Kris Kowal.

https://code.google.com/p/esprima/issues/detail?id=355
UnaryExpression should have prefix: true

https://code.google.com/p/esprima/issues/detail?id=418
Use single-quoted string literals.

https://code.google.com/p/esprima/issues/detail?id=398
For some demos, load Orion editor as early as possible.

https://code.google.com/p/esprima/issues/detail?id=404
Revert early loading of Orion code.

For a particular reason (not investigated yet), this causes the problem
in the demo itself.

https://code.google.com/p/esprima/issues/detail?id=404
Remove the (last) tracking function from binary expression.

Continuing the last refactoring to use the delegate and the marker,
this completes the abandoning of the special location tracking modifier.

https://code.google.com/p/esprima/issues/detail?id=355
Remove filterGroup.

As suggested by ZHANG Bei <ikarienator@gmail.com>, getting rid of the filter
should give some speed-up. Currently with V8 this leads to 1.4x faster parsing
on the benchmark suite (with location tracking).

https://code.google.com/p/esprima/issues/detail?id=417
Remove the need to extend the delegate.

This temporarily reduces the speed when parsing without location
tracking (about 7% with V8). No observable performance change
when parsing with location tracking.

https://code.google.com/p/esprima/issues/detail?id=355
Fix variance unit conversion.

This is also needed for browser-based benchmarks.

https://code.google.com/p/esprima/issues/detail?id=397
Catch clause should only accept an identifier.

https://code.google.com/p/esprima/issues/detail?id=423
Revamp the speed comparison test.

Focus on parsing with location tracking.
Use the upstream code for the parsers.

https://code.google.com/p/esprima/issues/detail?id=424