[CMake] CMake Version Compatibility Matrix

[Johannes Zarl]

Hi,

> Is there any chance that the version compatibility matrix will be
> updated for cmake 3.x features?

Short answer: no.

Longer answer:
I've written and maintained the compatibility matrix before.

The reasons I've stopped maintaining the page:
(1) Distilling the changes between versions is quite some manual effort (diffing 
the help text and checking whether something some change reflects a change in 
cmake or just a doc change) .
(2) The documentation format changed in cmake 3, which would have meant a very 
big one-time effort toget the differences between 2.8 and 3.
(3) I still believe that this could be done much better by including 
annotations in the documentation itself ("Available since:", "Deprecated 
in:").

Hope that explains my reasons,
  Johannes