Log Message:
Update to 0.5.0:

0.5
multi account support
support for more contenttypes/carddav servers
all vcards should have a UID (required by RFC 6352 and enforced by Owncloud 5)

0.4.2
searching for non ascii characters should work
doing an OPTIONS request now to check for carddav capabilities
  this should speed up the syncing process and increase compatibility (SOGo)

0.4.1
assorted bugfixes, see the git log

0.4.0
experimental write support in the backend
import & export vcards
import directly from mutt
speed increase in (initial) sync due to switching from pycurl to requests
detects removed cards on server and deletes them locally
can delete cards locally and on server
can handle base64 encoded images/sounds etc.