Modify android.syncml.pim so that no one is going to use.

- Remove android.syncml.pim.vcalendar since no one is using it.
-- We have android.pim.ICalendar.java, so handling vCalendar (== ICalendar) is possble without android.syncml.pim
- Mark android.syncml.pim.vcard and related code as obsolete.
-- Refactored version is in android.pim.vcard, which supports new Contacts database schema.

Related issue: 2110530