This pseudo-backend directory does not build a normal SyncEvolution
backend. Instead it just uses the autotools extension mechanism to
hook some source code into the SyncEvolution build and creates the
/usr/lib/sync/libsyncevo-buteo.so sync client plugin for Buteo.


It expose SyncEvolution's sync engine to Buteo. This must work without
prior manual configuration of SyncEvolution.

The approach will be something like this:
* create and install libsyncevo-buteo.so sync client plugin
* define "Google Calendar" service using it
* configure it in sync UI
* during sync, create or update "google@default" local sync
  config, with "target-config@google" for remote CalDAV access

Because of the limited applicability of the plugin, hard-coding
specific services is okay.
