[cmake-developers] option to prevent in-source builds

[Ben Boeckel]

On Fri, Nov 09, 2018 at 07:28:54 -0500, Taylor Holberton wrote:
> A lot of projects that use CMake already have a `./cmake` directory, I
> would think `./cmake/init.json` would fit nicer as opposed to the hidden
> directory. I'm not a fan of hidden directories in software projects anyway.

There are also `./CMake` directories. HDF5 uses `./config/cmake`. I
think just claiming a "hidden" directory with exact casing is better.

--Ben