fixed imap list cmd selector

Binary actually contains an empty string, rather than being empty.
removed R16 support
Merge pull request #32 from jtmoulia/list-fixes

IMAP LIST fixes, dropped R16 support.
added vagrant installation
improved documentation, fixed bullet lists
Merge pull request #34 from jtmoulia/vagrant

Added Vagrantfile and Ansible provisioning, vsn -> 0.2.0