Making ccrtp propagate its build time requirement, ucommon.
As libccrtp propagates ucommon, it's not needed in libzrtpcpp.
Update ucommon to 6.0.5.

The hope that newer means better.
Adding partially sflphone (only daemon, maybe failing to build)
Making sflphone build, and its gnome client too.
Adding sflphone.

Merge branch 'sflphone'