This adds recipe-maintainers section in meta.yaml, inspired by conda-forge.
There is no automated usage for this section yet, but it suggests who we can ping if
something is wrong with a package. In the future, we may make a tool that automatically
notifies recipe maintainers.
Split off from #4468 / #4435 for visibility because it's a bit troublesome.
clang gives a weird error saying that qsort and memcmp were not declared.
This despite the fact that the file in question imported stdlib.h where they
are declared.