[gtk] (24 commits) ...Merge branch 'modern-testsuite' into 'master'

[Benjamin Otte <otte src gnome org>]

Summary of changes:

  b6d3561... testsuite: Be more verbose in texture-threads test (*)
  a4f3fbb... gltexture: Fix download() for GLES (*)
  551f76e... gltexture: Fallback in download_float() (*)
  64acaf9... testsuite: Fix race in texture-threads test (*)
  75dfb4d... API: Add gdk_texture_new_from_filename() (*)
  de53b0c... testsuite: remove box-order test (*)
  3a8ec68... reftests: Make diff pixels always opaque (*)
  0dfab46... reftests: Use GdkTexture instead of cairo_surface_t (*)
  390a0b2... ngl: Fix opacity handling (*)
  46bb160... testuite: Add opacity-overdraw test (*)
  c84d5b1... tests: Update rendernode test to use textures (*)
  625b5ce... testsuite: Port compare_render() to use textures (*)
  90ed7b9... reftests: Use 0.6 alpha, not 0.5 (*)
  4733059... reftests: Use 0.6 instead of 0.5 for alpha (*)
  58f66eb... reftests: Make image-compare use textures (*)
  7cf5e55... testsuite: Switch color from khaki to yellow (*)
  62954a0... ngl Fix bottom-right border render failure (*)
  9e14de2... ngl: Improve shortcuts for shadow nodes (*)
  93323be... ngl: Avoid offscreens in more cases (*)
  56b31c3... rendernodeparser: Handle is_color attribute for glyphs (*)
  08df891... reftests: Use colors without rounding errors (*)
  345faa7... reftests: XFAIL border-half-pixel test (*)
  83ea623... reftests: Use the default (aka NGL) renderer (*)
  698b354... Merge branch 'modern-testsuite' into 'master'

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