[gtkmm] (15 commits) Non-fast-forward update to branch use-dllexport-3-24

[Chun-wei Fan <fanchunwei src gnome org>]

The branch 'use-dllexport-3-24' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  30af1e4... gdk/gdkmmconfig.h.in: Add GDKMM_API
  649891c... gtk/gtkmmconfig.h.in: Re-organize GTKMM_API definitions
  5376acb... gdk/src/*.hg: Mark classes and functions with GDKMM_API
  b5a32aa... gdk/gdkmm/*.h: Mark functions with GDKMM_API
  19d33c6... tools/m4/class_gtkobject.m4: Allow applying decorations
  bcc10d3... gtk/src/*.hg: Mark classes and functions with GTKMM_API
  36485da... gtk/gtkmm/*.h: Mark functions with GTKMM_API
  9f92bbb... NMake Makefiles: Export symbols without gendef if possible

Commits added to the branch:

  8d836ca... Fix build with X11 backend disabled (*)
  b3f26cc... docs/reference/images/stock: Remove .svg files (*)
  b546b96... gtk/gtkmm/filelist.am: Remove border.h (*)
  31f8b8a... NMake Makefiles: Use /utf-8 if available (*)
  6259e6b... NMake Makefiles: Fix build rules (*)
  b7f10c3... NMake Makefiles: Fix previous commit on /utf-8 (*)
  735c661... gdk/gdkmmconfig.h.in: Add GDKMM_API
  a4026ce... gtk/gtkmmconfig.h.in: Re-organize GTKMM_API definitions
  6a18b21... gdk/src/*.hg: Mark classes and functions with GDKMM_API
  2acdb83... gdk/gdkmm/*.h: Mark functions with GDKMM_API
  d0a9ad2... tools/m4/class_gtkobject.m4: Allow applying decorations
  c123cf9... gtk/src/*.hg: Mark classes and functions with GTKMM_API
  7cbbca9... gtk/gtkmm/*.h: Mark functions with GTKMM_API
  6feac83... NMake Makefiles: Export symbols without gendef if possible
  703c980... NMake Makefiles: Ignore warning C4273

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