Parser demo should use comment attachment.

Since attaching comments to the syntax node is implemented, this is what
should be instead and not just comments collection.

https://code.google.com/p/esprima/issues/detail?id=197
Update code coverage report.

http://code.google.com/p/esprima/issues/detail?id=388
Minimize the payload for npm.

Selectively choose which files to include in the module (for npm).
Currently, this is known to break npat=true when doing npm install.

https://code.google.com/p/esprima/issues/detail?id=493
https://code.google.com/p/esprima/issues/detail?id=510