ftp: add type specs
ftp: add type specs

bjorng/otp,erlang/otp,bjorng/otp,bjorng/otp,bjorng/otp,erlang/otp,bjorng/otp,erlang/otp,erlang/otp,bjorng/otp,erlang/otp,erlang/otp,erlang/otp,erlang/otp,bjorng/otp,erlang/otp,bjorng/otp,bjorng/otp,erlang/otp,bjorng/otp