[geary] (9 commits) ...Merge branch 'mjog/meson-cleanup' into 'mainline'

[Michael Gratton <mjog src gnome org>]

Summary of changes:

  187f2b7... Bump minium GLib version to last known good (*)
  ea9e08e... Don't explicitly specifify --glib-version, meson does it fo (*)
  64f14b4... Update valadoc target (*)
  f5f9350... Consistently use '_dir' suffix for meson directory variable (*)
  af29157... Consistently use '..._c_args' and '..._vala_args' for meson (*)
  cf8ea7e... Sort meson config options (*)
  4a959ab... Move source build config from top-level to src meson.build (*)
  8e08b0e... Tidy up top-level meson.build file (*)
  afa83c5... Merge branch 'mjog/meson-cleanup' into 'mainline'

(*) This commit already existed in another branch; no separate mail sent