[libcontacts] Do not start timers during application close. Contributes to MER#1267

[libcontacts] Report invalid addresses as unknown. Contributes to MER#1260

An invalid address should result in a resolution-to-no-contact event.

Improve address resolution behavior

Otherwise, existing resolutions may not be updated by the addition of
better matches.

[libcontacts] Adjust fetch hint for non-completing address resolution.  Contributes to MER#1174

When resolving an address that does not need the whole contact to
be retrieved, the fetch should include any resolvable addresses of
the contact, since address resolution is obviously in use in the
caller application.

[libcontacts] Correctly initialize status flags. Contributes to MER#1206

[libcontacts] Fix unit tests

Commit 813eafc0 changed how formatted
name (FN) properties from vCards are imported, so that now an import
involving de-duplication can result in a single contact with multiple
nicknames (setNickname() actually adds nicknames if the new nickname
does not match a previously set nickname).

The contact cache provided by libcontacts is intended for use by
privileged applications only.  Its functionality does not make sense
for non-privileged clients, and cannot be tested correctly when
run in non-privileged mode.

[libcontacts] Add API to support PHOTO processing in client code

This commit adds API to allow clients to use libcontacts' standard
implementation of processPhoto() for handling PHOTO vCard properties
in their own vCard handling implementations.

[libcontacts] Some scripts imply name token ordering

For a specific set of character scripts, if a contact's first and last
names are entirely composed of that script, then that (most likely)
implies a cultural ordering for given/family name tokens that should
override the device setting.

Fix UI freeze on first start

[libcontacts] Improve vCard contact import API

This commit improves the SeasideImport API by allowing clients to
specify their own SeasideContactBuilder implementation when
converting the list of Versit documents into storage QContacts.

The SeasideContactBuilder allows the client to parametrise things
like the contact filter used to determine the subset of mergable
contacts, the merge strategy to use, and so on.

Parts of commhistory (GroupManager) will send a stream of
resolve requests with many duplicates. This used to be
tolerable because requests were handled slowly in the
event loop, but now that they have higher priority it has
become a problem.

I went for the simple solution of ignoring requests that
are identical to still-active requests (same uids, same
listener, same requireComplete flag). It's not optimal (we
could combine more requests into the same backend query if we
tried), but it solves the problem without adding a lot of
bookkeeping.

This QList was not scanned when unregistering a listener, even though
it does contain listener pointers.

[libcontacts] Prioritize requests that make app startup more responsive

change suggested in review by mvogt

This change does not affect normal performance but it guards
against bad performance when there are many resolve requests.

Thanks to Matthew Vogt for the idea.

resolveAddress requests are done with one query at a time, in
order to correlate the results with the looked-up addresses.
Doing them sequentially via UpdateRequest events added a lot
of overhead in the form of coordination between threads.

This commit creates a dedicated QContactFetchRequest for each
resolveAddress call, so that the events for starting them can
arrive all together in the backend thread and the events
announcing the results can arrive all together in the UI thread.
They will still be processed sequentially, but this change cuts
out the delay between finishing one request and starting the next.

In tests with 10k contacts and a recent contacts list with limit=20,
this reduced the resolve time from 1s to 0.3s.