ftp tests should stop complaining about medusa

[Robert Collins]

with the new Feature logic we should stop warning on the console about missing medusa, instead we should parameterise all the transport tests for ftp *anyway* but have them parameterised to check for the medusa feature. This will mean that only attempts to run the tests needing medusa will complain at all about it.

[John A Meinel (jameinel)]

I think the easiest way to accomplish this is to give another entry returned by 'get_test_permutations'. Which would include a "Feature" which these tests depend upon.

This would also include doing the same thing for paramiko and the sftp tests.

[Vincent Ladeuil (vila)]

I think this was addressed quite long ago and 1.14 starts to obsolete medusa for python2.6 anyway.