Hey Zack,
I have pushed the working version of http_apache_steg_t. On server side it asks apache for the load, on the client side it uses the url dictionary and parameter values.
http_apache_steg_t is inherited from http_steg_t. But because of all those macro hackish tricks (which expect you to inherit only from steg_t), it feels bit odd (when c++ natively support polymorphism maybe we don't need these macros). So you can test it writing http_apache instead of http in the command line. (but you need apache installed on server side and you need to run payload_scraper first)
Downstream client to server is only curl now and hence probably more robust while passing proxies. It's blocking though. I'll make non-blocking in near future.
I'm going to implement the protocol for passing the dictionary from the server to client in following few days and spends next week testing, writing tests and applying your comments on github (including spelling and grammatical mistakes :p )
Cheers, vmon
P.S. I'm slowly re-styling stuff in the steg directory to c++ style, meanwhile it might look even uglier and messier, but it'll be pretier at end.