Rewrote first batch.
Rewrote second batch.
Rewrote existing test suite in mocha.

All tests pass, run with memory, redis and mongodb backends.
Updated readme and package.json.
Added mocha and chai as devDependencies.
Merge remote-tracking branch 'upstream/master' into mocha-tests

Conflicts:
	Readme.md

To avoid merge conflicts later.
Make test runner little more dry.
Added test for #32.
Break test down into several parts.

Fixes #32.
Merge pull request #35 from diversario/i32-mongodb-remove-role

#32 mongodb remove role (although error was actually in acl.js)