tls: fix some error handling.
echo: add server echo channel api.
Implemented thread handling for WaitForMultipleObjects.
Implemented thread specific functions.
Now using thread_launcher function to properly clean up thread resources at exit.
Removed noreturn from ExitThread, does not conform to http://msdn.microsoft.com/en-us/library/windows/desktop/ms682659%28v=vs.85%29.aspx and crashes FreeRDP.