See [LLVM Coding Standards](https://llvm.org/docs/CodingStandards.html#avoid-std-endl)

Setting this as default option does not work with meson 0.45.1

As the students' implementation of the pi2 is not free software,
we have to relicense the pi2-view library to allow linking
with non-free software.

GCC does not know the clang diagnostic pragma.

This allows us to toggle our entire project
from shared to static with only one option.

Ignore redeclaration of `struct MapApp` as `class MapApp`
in implementation of MapAppABI.