Remove packages directory

Just rely on mr as yet another dependency.
Conflicts:
	packages/mr/.gitignore
	packages/mr/bootstrap.js
	packages/mr/browser.js
	packages/mr/package.json
	packages/mr/require.js
	packages/mr/spec/README.md
	packages/mr/spec/comments/program.js
	packages/mr/spec/not-found/program.js
	packages/mr/spec/require-spec.js