[pan] (21 commits) ...Merge branch 'fixup-for-merge'

[Dominique Dumont <ddumont src gnome org>]

Summary of changes:

  495bfb2... Fix for GMime3 build (Posting error). Issues #103 and #114
  0d77554... Remove empty line from file posting.xml
  39ba1ad... Take <glib.h> out of extern "C"
  8cf0cff... Merge https://gitlab.gnome.org/GNOME/pan
  e7f5802... Merge branch 'fix-mess-from-glib-update' of https://gitlab.
  af7c6df... Additional fixes for issue #128 when Pan is build with some
  3b35d8b... Fix two compile errors when build with GMime3
  552d383... X-Face: manual folding for length >72.
  ad830b0... Header fix for Arch Linux compilation.
  5f5b07c... Merge xface-fix with compile-fix
  a5c8e42... Added experimental support for sending Face header.
  0f36c31... Fix merge conflict.
  493de9d... Fic forgotten conflict.
  a91de9d... Another forgotten conflict fix...
  3fc114e... Applied Face/X-Face patches to GMIME3 code.
  682888d... Supposed fix for posting icons.
  a04993b... Compile fix: gtk_handle_box_new() to gtk_box_new()
  04f2bf5... Updated source code to latest upstream commit.
  425cc58... Merge commit '4dbec01e' into 'master'
  fa5f1f6... Removed #include duplicates.
  4d6592a... Merge branch 'fixup-for-merge'