Implement HTTP Utility Classes

As discussed, this is needed for Node.js to be able to make calls directly. This shouldn't require too much prototyping because we pretty much know what this should look like from what we have in LCB currently, but please show Brett the interface first to make sure there aren't any surprises.

Notes from our working session on this topic.

• We will introduce an HTTP helper (similar to LCB) but should strive not to use this for management APIs when possible (better to use common code).
• Any wrappers that use this method have to create their own corresponding unit tests since CB++ tests will not be used.
• Node.js will use the HTTP helper for now and we’ll look to refactor later.