added per collection index for contacts

this is needed to delete all contacts from one collection, i.e.
if a folder is deleted/deselected for sync remotely.

Open-WebOS-DCO-1.0-Signed-Off-By: Achim Königs <garfonso@tratschtante.de>
fixed home folder discovery

was broken for all servers. Now at least works with my egroupware server.

Open-WebOS-DCO-1.0-Signed-Off-By: Achim Königs <garfonso@tratschtante.de>
fixed collection sync

collections were never deleted locally... that now works again.
Also local objects in that collection were not deleted.
Added that.
Also prevents local deletes during the collection deletion to propagate
back to server.

Open-WebOS-DCO-1.0-Signed-Off-By: Achim Königs <garfonso@tratschtante.de>
minor fixes & typos

Open-WebOS-DCO-1.0-Signed-Off-By: Achim Königs <garfonso@tratschtante.de>
empty upsync would lead to slow downsync

this is now fixed, error state is only set to true, if there where
local changes to sync up. If that works, error state goes back to false.
But if that never starts, error state never went back to false.

Open-WebOS-DCO-1.0-Signed-Off-By: Achim Königs <garfonso@tratschtante.de>
fix down throw on upsync on 412 error

412 means there are changes on the server, too. So upsync failed.
If we throw here, the syncKey would never be stored => slow downsync
with error state would never happen (or only when there are changes on
server) and we are trapped in an endless loop with no changes able to
propagate to server.

Open-WebOS-DCO-1.0-Signed-Off-By: Achim Königs <garfonso@tratschtante.de>
disabled postPutRemoteModify

this is because the patch "sync-fix-for-stable-upload" is broken.
It produces an endless loop (which consumes a lot of system ressources
and will drain all battery FAST!), because revs for the local objects
don't get updated correctly. Patch author tried to be too smart... :(
Downside of not having postPutRemoteModify is that etags don't get
stored locally, so the changed objects transmitted to server will be
downloaded again on next downsync, because etag differs.

Open-WebOS-DCO-1.0-Signed-Off-By: Achim Königs <garfonso@tratschtante.de>
Merge pull request #3 from Garfonso/master

collection sync and discovery fixes