[libcontacts] Do not postpone fetching indefinitely

QElapsedTimer now isValid() on construction, without having started;
it must be explicitly invalidated at startup.
Merge pull request #3 from matthewvogt/fix-fetch

[libcontacts] Do not postpone fetching indefinitely
[libcontacts] Export name group members for potential filtration

The NameGroupModel may wish to filter the members of each group.
Merge pull request #4 from matthewvogt/export-group-members

[libcontacts] Export name group members for potential filtration
[libcontacts] Fix qt4 build
Merge pull request #5 from matthewvogt/qt4-fixes

[libcontacts] Fix qt4 build
[libcontacts] Filter contacts by address type without QContact data

Allow address type filtering to be performed without retrieving the
full QContact object.
Merge pull request #6 from matthewvogt/status-flags

[libcontacts] Filter contacts by address type without QContact data
[libcontacts] Make contact browsing faster

Pre-fill the cache with contact metadata rather than entire contact
records.  Where a particular address type is required for selection by
an attached model, include that address type in the queried data.

Also allow partially loaded contacts to be completed, and contacts to
be queried by address, whether already present in the cache or otherwise.
Merge pull request #7 from matthewvogt/partial-contacts

[libcontacts] Make contact browsing faster
Qt4 fixes
Merge pull request #8 from matthewvogt/qt4-fix

Qt4 fixes
[libcontacts] Add API for name grouping.

Allow a customized name grouper to be set.