Switch to common.js require, browserify, and istanbul.
package.json: Simplified browserify command line.

Turns out it reads the "main" field itself.
Put the license in a separate file and make sure it appears at the top of the browserified bundle.
README: Refer to the license.
package.json: Added license field.
package.json: Moved browserify to devDependencies.
Added bundle-collapser browserify plugin.

Saves 121 bytes in the uglified and gzipped output.
Merge pull request #1 from papandreou/browserify

Switch to common.js require, browserify, and istanbul.