YADE should support FTP pre- and post-commands

Current Situation

• YADE allows FTP commands to be executed at the beginning and of the session before and after file transfer.
• See https://en.wikipedia.org/wiki/List_of_FTP_commands
• This feature is broken as FTP commands interfere with NOOP operations executed by YADE
• To reproduce this error use 01_01_ftp_options_JADE-347.ini with the profile ftp_server_2_local_processing

Desired Behaviour

• FTP commands as stated in the Wikipedia article should work