package: add "browserify" as a dev dependency
Makefile: refactor to use browserify

Uses browserify to build a `dist/debug.js` file for
standalone browser-side consumption.
npmignore: don't publish the `dist` dir

Not used in node/browserify, so not needed.
dist: recompile
Merge pull request #101 from visionmedia/use/browserify

Use "browserify" for standalone browser-side builds