[libcommhistory] Add Recipient and RecipientList

Recipient represents a remote account or phone number, replacing use of
localUid+remoteUid pairs. It offers API for consistently comparing UIDs,
along with better behavior for contact resolution.

RecipientList is a convenience API for a list of recipient.
[libcommhistory] Rewrite ContactResolver to use Recipient and libcontacts

ContactResolver now resolves for a Recipient, rather than an Event,
enabling its use for groups and other situations. SeasideCache is used
to resolve contacts directly, instead of through ContactListener, which
dramatically improves performance.
[libcommhistory] Refactor ContactListener into a change listening API

ContactListener can no longer be used to resolve contact addresses;
ContactResolver should be used instead. ContactListener now listens for
changes to contacts that affect existing instances of Recipient, and
emits signals for them.
[libcommhistory] Use Recipient for Group API
[libcommhistory] Use Recipient in Event API
Optimize localUidComparesPhoneNumbers function

Using QLatin1String saves us a lot of time in converting the string as
UTF8, and it's a simple function, so inlining makes sense.
[libcommhistory] Remove unused declarative ContactAddressLookup type

This isn't as useful with improvements made in nemo-qml-plugin-contacts
and libcommhistory's contact resolution since it was written. It no
longer has any users, and would require maintainence to keep.
Remove ineffective requiredProperty API from RecentContactsModel
Add Qt-style headers for several classes
XXX Debug
WIP Disable tests