[WIP] Feature/fix libmproxy 1269

Issue #1269 

 - [x] spiderman works with libmproxy
 - [x] localproxy works with libmproxy
 - [x] sqlmap works with libproxy
 - [ ] Add more unittests for Proxy and w3afHandler
Add a clean-up sub-task somewhere in your TODO list to:
 * Remove the proxy.py file and run tests. Make sure they PASS. This verifies that there is no reference to the old module.
 * Rename proxy2.py to proxy.py
 * Run tests and make sure they PASS