Made http_req_t::resource_t use a vector<std::string> instead of a tokenizer.  Also, slightly changed its behavior.
Made HttpResourceTest.Slash reflect new reality.
Renamed _val to val in resource_t constructor.
Removed boost tokenizer, boost string headers in http.hpp/cc.
Made resource_t disallow creation of empty resource.
Adjusted users of as_string for the fact that you cannot have an empty resource.  Made file_http_app_t not bypass whitelist with index.html.