Added port listing feature
We don't require a .ctproject file anymore
Few fixes

 * netcat on debian was not working, added a detection routine to use the proper syntax
 * when no open port was found, json was incorrect (' ]') instead of ('[ ]')
Simplified parameters reading

Thx @tdebarochez
Updated README.md

README now explains what is possible to do with port scanning
Merge pull request #5 from code-troopers/feature/listPorts

Added port listing feature to ct