Sorting and searching in PBAP address book caches must be fast, which depends
on adding the right fields to the summary tables.

For address books created by EDS, this needs to be done by SyncEvolution. There
is no good way of using text template files for the configuration (something
that Matthew Barnes wants to add, but didn't get around to), so hard-code it in
C++?

For the system address book, the distro needs choose how it configures that.
Must be a distro patch for EDS.

TODO: determine the right configuration.