[gtk+/wip/baedert/gl] (25 commits) ...gl renderer: Avoid some code duplication

[Timm Bäder <baedert src gnome org>]

Summary of changes:

  f92cca5... gl renderer: Fix release build (*)
  c1573a1... window: Avoid a set-but-not-used warning (*)
  73d6076... css docs: Fix some angle brackets for percentage (*)
  3c7c4a0... css docs: Get rid of non-breaking spaces (*)
  98a28f4... css docs: Get rid of non-breaking hyphens (*)
  ccf3b10... css docs: Ensure the first column does not break for every  (*)
  b3871a7... css docs: Fix refentry and refname (*)
  b42fc41... css docs: Fix duplicate border‑right‑width (*)
  ea55471... css docs: swap border-width and border-left shorthands, to  (*)
  c1ce599... css docs: remove useless <para> (*)
  ed5f07e... css docs: fix some formatting inconsistencies along the way (*)
  25523e6... gtk: remove non-breaking space, probably there by mistake (*)
  9c1207e... Update new css docs for new nowrap handling (*)
  7d659b2... Drop deprecated text view layers (*)
  1268440... inspector: Stop using GtkWidget::event (*)
  da74314... treeviewcolumn: Stop using GtkWidget::event (*)
  74f563b... text handler: Stop using GtkWidget::event (*)
  1be0b6d... dnd: Drop docs that are no longer relevant (*)
  72c9853... list, flow box: Make unpaired releases opt-in (*)
  17bad98... emoji: Accept unpaired releases for variations (*)
  98f5d68... css parser: Reuse one GString
  d323cf3... gl renderer: Restrict textures to current clip
  aa03299... gl renderer: Remove an unnecessary block
  b5308eb... gl driver: Remove some type checks in a hot path
  fa035e3... gl renderer: Avoid some code duplication

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