Merge branch 'kn/meson-hdr-check'

Add an equivalent to "make hdr-check" target to meson based builds. * kn/meson-hdr-check: makefile/meson: add 'check-headers' as alias for 'hdr-check' meson: add support for 'hdr-check' meson: rename 'third_party_sources' to 'third_party_excludes' meson: move headers definition from 'contrib/coccinelle' coccinelle: meson: rename variables to be more specific ci/github: install git before checking out the repository