Added the methods to fetch the contacts from device and also the
contacts from the server. Added method setToken() and setUpdatedMin to
manage the run-time http transport properties. Next step is to add meat
to the signal and slots of GTransport and GContactClient and tie up the
flow.

Signed-off-by: Sateesh Kavuri <sateesh@mobilitas.co>
Added methods to creates the list of added/modified/deleted contacts
from server.

Signed-off-by: Sateesh Kavuri <sateesh@mobilitas.co>