[ENHANCEMENT] Update http.go to recognize/use "Direct" boolean

[parsley42]

This should be part of a larger effort to make the language integrations "thinner". Currently, e.g. Say* and Reply* are implemented in the language library, duplicating logic in the engine core and complicating the library files. A better approach would be more similar to e.g. gopherbot_v1.lua, where all the methods are very light-weight wrappers that just pass args straight to the engine, which makes all the real decisions.