Add Single Shell Python Bind Payload

I'm using this as I have a SAP router that forwards traffic but there is no route back.


I guess it is compatible with python 2.3.3 thanks to the usage of popen3. Just noticed it is deprecated in python. I'm a python ignorant, not sure what deprecation means in the python world. I mean, not sure if the API will be deleted in the future. If it's the case I don't know how close is this future. Maybe worths to make it and shell_reverse_tcp also compatible with the new subprocess module? Thoughts?