Added Options for libc base and canary

Exploit is working for me now on Ubuntu 13.04. I added options to set the canary and libc base. I'm still not sure where the 200 responses came from, I think I had an older version compiled on my other machine (also I think the URL must exist, so no 404 response, we can put that into an option as well).
For the buffer try changing your victims IP address from 192.168.1.xx to 192.168.1.xxx (note different length), it should break the exploit. To get the total offsets you need to add 153 to all offsets (I think).
I'm not sure what the best way to send the HTTP requests would be then, we can always craft them manually but maybe there is a better way?
Once that is done I will take care of the buffers, the hex digests in the first 1024 - header length bytes need to add up to a negative 64bit number or else it won't work.