Fixes for RAW and PASV/PORT commands

This is my first pull request, so I am unsure about the amount of verbosity required, hopefully I can make it more clear with output given by FTP server when PORT command sends an array:

Net::FTP=GLOB(0x18ffbd8)>>> PORT ARRAY(0x1921fb0)
Net::FTP=GLOB(0x18ffbd8)<<< 500 'PORT ARRAY(0x1921fb0)': Command not understood.

Other one doesn't really produce an error, but it's somewhat obvious that it won't show anything on case sensitive filesystems :-)