This patch adds additional API for setting the stroke/fill
properties of vector layers. You can now set/get color, stroke
width and stroke style via the PDB. Pattern get/set API is not
yet implemented.
This patch also updates a missing parameter check for GimpVectorLayer
in gimp_config_param_spec_duplicate (), and adds additional API
in /app to make it easier to safely retrieve GimpVectorLayerOptions.
This patch improves vector layer UX based on feedback.
In summary:
* Makes vector layer editable from the Path tool
* Adds initial PDB for creating vector layers in scripts
* Size vector layers to the path size, rather than image
* Transform tools utilize the path for resizing
* Path tool automatically selects vector layer path
