RFC: Initial Browser Support

/to @raymondfeng @bajtos

**Do not merge**

Right now this is only ready for code review. This builds on `feature/replication`... which in hindsight was probably a mistake. LMK if this needs to be separated out for review.

**Priority for Review**

Take a look at the browser example. This is what should be reviewed. Major implementation details should also be taken into account. Leave minor issues for the merge-able PR.

**Bundling** 

The browser distribution is bundled using browserify.

**Testing** 

**Note:** ignore `bin/test-browser.js`. This will be removed.

The loopback mocha tests are run via the test server. See `test/browser`. We still needs CI testing. The gruntfile includes some initial work on this.

**Server Connector**

This is the mechanism for connecting a browser based app to a loopback server. It supports the basic DAO. It also adds support for `remoteModels`.

**loopback.models()**

This is a middleware (probably should be refactored into a basic method + middleware) for building a `loopback-remote-models.js`. This is used by the `loopback.Server` connector to discover and define models in the browser.