Create a RESTful API

The original PythonDirector had a RESTful API of sorts. Due to old code issues, it wasn't carried over. However, txLB needs one as well.

I have a Twisted-based REST Resource library that I can add to txLB to provide just this sort of functionality. It is very similar to the Twisted JSON-/XML-RPC servers. From the client (user) perspective, one will simply point at a URL, provide some paramaters (query string), and get the needed data.

From the code perspective, I will do the following:
 * create a txlb.web subpackage
 * move txlb.admin to txlb.web.admin.
 * add my Twisted REST server support to txlb.web.rest
 * create the module txlb.web.api, where a general API will be defined and used to create XML-RPC, JSON-RPC, or REST APIs