removed unused import of Unix-only module 'fcntl' from mailpile/crypto/streamer.py
removed unused import of Unix-only module 'fcntl' from mailpile/crypto/symencrypt.py
Unix-only module 'fcntl' is now imported within GnuPG.run within try-except-ImportError to make this module importable under Windows, to allow Windows-developer reimplement GnuPG.run with althouth-Windows modules
import of Unix-only module 'readline' now within try-except-ImportError to make this module importable under Windows
added 'markupsafe' and 'nose' to the required third party packages, but without version number
Merge pull request #606 from dlmueller/master

Make mailpile importable under Windows