fixed carddav-discovery did set wrong namespaces
fixed issue with VTODO and possible empty ics files.
fixed content-type on vcard/vcalendar download.
changed content type of xml requests

application/xml should be fine, too, not? But somehow the
yahoo server was not lucky with it... so I changed it into
text/xml. I tried all other server, which were ok with
text/xml, too. So I guess it is got to keep it this way.
enabled URL scheme for yahoo.
fixed carddav/caldav selection in syncassistant.
in some circumstances error state was forgotten after failed sync.
fixed possible hang in checkcredentials
whitespace changes in urlschemes.js
added yahoo account template
0.2.9