Merge branch 'kn/meson-hdr-check'

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