RefR and RefAngle of polar handles of custom shapes can be handled
now. Their values in oox-drawingml-cs-presets and the loader of
preset shapes are updated accordingly.

Change-Id: Icacb19fbd1f4c202950b0a19afce01ad1cafc82a
Reviewed-on: https://gerrit.libreoffice.org/30602Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Mark Hung <marklh9@gmail.com>