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
moved fflush into Trace() macro
replaced own Ip int to string convertion with inet_ntop() posix call
start implementing mClientSock as TcpSocket
mutex is not necessary since there is only one thread writing to mFtpServerRunning
remove redundant TcpSocket implementation
removed redundant Select() implementation
refactored close mClientDataSock() into a function
reused closeDataConnectionWithException()
x
refactored TcpServerSocket
adjust unittest
fix unittest
use relative firmware path
xcode change
Merge commit '2bdc8e4803dd3adada6897f4eb5963c7f0305874' into ftp_test
fix unit test