Merge topic 'gitignore-build'

2c1ab065fe gitignore: Tell Git to ignore build*/ directories

Acked-by: Kitware Robot <kwrobot@kitware.com>
Acked-by: Alex Turbov <i.zaufi@gmail.com>
Acked-by: مهدي شينون (Mehdi Chinoune) <mehdi.chinoune@hotmail.com>
Merge-request: !7283