cleanup of jingle_transport.py

Correctly verify remote SSL certificate.

Name of filetransfer content is now random to be able to have 2 transfer in the same session. send and handle content-add in filetranfer

 - Don't use XTLS when using proxies

TODO: implement file transfer complete callback, various session management code for abnormal FT interactions.

Also use sed to remove now unneeded Vim lines, 2to3 -f ws_comma to fix
some whitespace, and fix some other madness manually.

also use 2to3 -f ws_comma to fix some whitespace

holy diff batman!