This gives us 9 flags available again for properties (we had none anymore), and also makes things slightly cleaner. To simplify (and make more clear the differences between mere properties and function parameters), also added RNA_def_parameter_flags function (and its clear counterpart), to be used instead of RNA_def_property_flag for function parameters. This patch is also a big cleanup (some RNA function definitions were still using 'prop' PropertyRNA pointer, etc.). And yes, am aware this will be annoying for all branches, but we really need to get new flags available for properties (will need at least one for override, etc.). Reviewers: sergey, Severin Subscribers: dfelinto, brecht Differential Revision: https://developer.blender.org/D2400