Merge lp://qastaging/~cemil-azizoglu/mir/enum-deprecation into lp://qastaging/mir

Renaming enums conveniently while not causing ABI break twice is a PITA.

I want to be able to create a new enum type (MirWindowAttrib in this case) which is type-equivalent to the existing MirSurfaceAttrib so various internal functions can take either as well as the renamed functions.

I also want to introduce new enum values that are equivalent to the old ones (e.g. mir_window_attrib_type <--> mir_surface_attrib_type) so downstreams can use the new ones instead of the old ones.

So I was thinking we make the changes in this MP and adapt the downstreams, which is fine at first. But then when we are ready to deprecate we would need to delete the mir_surface_attrib_* values and let the others remain. But that causes another ABI break - at least that's what abi-compliance-checker reports. I do believe it's a false-positive but nevertheless I wanted to ask.

Is this ok? It also has the downside that there is no way to mark individual enum values as deprecated. Is there a better (and still convenient) way?

I guess I can mark the individual values deprecated as follows

...
     mir_surface_attrib_type __attribute__((deprecated)),
...