Flexible space for constraints
This branch applies on top of the constraints branch. It adds
- GtkConstraintTarget as a marker interface for objects that can be used in GtkConstraint as target and source
- GtkConstraintGuide as a constraint target that is not a widget and can be used as either a guideline or as flexible space
- Fixes to the 'internal consistency' constraints
Open questions:
- Do guides need min/nat size as properties? You can just set constraints yourself...
- If we keep min/nat size, do we want max size too? Easy to do with constraints
- Are constraint target and guide the best names ?
Edited by Matthias Clasen