Merge branch 'ps/meson-contrib-bits'

Merge branch 'ps/meson-contrib-bits'

Update meson-based build procedure to cover contrib/ and other
places as well.

* ps/meson-contrib-bits:
  ci: exercise credential helpers
  ci: fix propagating UTF-8 test locale in musl-based Meson job
  meson: wire up static analysis via Coccinelle
  meson: wire up git-contacts(1)
  meson: wire up credential helpers
  contrib/credential: fix compilation of "osxkeychain" helper
  contrib/credential: fix compiling "libsecret" helper
  contrib/credential: fix compilation of wincred helper with MSVC
  contrib/credential: fix "netrc" tests with out-of-tree builds
  GIT-BUILD-OPTIONS: propagate project's source directory