added complete test loop for FtpServer functionality

NOTE: this test is implemented as a shell script for now, this might be incompatible with OSX!
- The timeout detection in FtpServer.cpp was disabled to allow localhost connections, this will be fixed during the refactoring, which I start next
- the hardcoded path was changed to fit my environment
- after successful refactoring we can try to implement the unittest as c++ program, but should have a short discussion on that