[gtk] (20 commits) Non-fast-forward update to branch wip/baedert/for-master

[Timm Bäder <baedert src gnome org>]

The branch 'wip/baedert/for-master' 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:

  2e1a231... testblur: Fix default blur radius
  8cdceb0... gl renderer: Blur shader improvements
  325de75... gl renderer: Add some often needed debug code
  ff07b1a... gl renderer: Scale blur radius
  ba96c2b... gl renderer: Take a TextureRegion in blur_texture
  88449ef... gl renderer: Implement blurred shadow nodes
  8e2cefa... snapshot: Factor out color matrix merging
  828e523... snapshot: Reorder color matrix nodes containing a transform
  3c015ac... window: Don't set invalid csd input shape
  5ef0d55... gl renderer: Save one level of indentation
  d3290db... cssshadowvalue: Simplify inset shadow nodes to color nodes 
  2944d4e... gl renderer: Cache current scale in RenderOpBuilder
  f31fed1... testsuite: Add an inset shadow rendering test case
  1778a58... opbuffer: Remove unused op member
  5059fe2... gl renderer: Remove unused uniform from inset shadow shader
  9842daf... gl renderer: Implement blurred inset shadow nodes

Commits added to the branch:

  e81a90c... window: fix opaque region (*)
  87ea025... themes: remove various @extend with compound selectors (*)
  619c892... Merge branch 'sass-no-extend-compound-master' into 'master' (*)
  ab32b1b... Merge branch 'wip/muktupavels/opaque-region-master' into 'm (*)
  7862ab3... testblur: Fix default blur radius
  4eedbfe... gl renderer: Blur shader improvements
  eed9c3d... gl renderer: Add some often needed debug code
  cc1ecf1... gl renderer: Scale blur radius
  4e602da... gl renderer: Take a TextureRegion in blur_texture
  82440a8... gl renderer: Implement blurred shadow nodes
  f316f50... snapshot: Factor out color matrix merging
  2d70b70... snapshot: Reorder color matrix nodes containing a transform
  ff3cdc1... window: Don't set invalid csd input shape
  5defbf7... gl renderer: Save one level of indentation
  0ebef11... cssshadowvalue: Simplify inset shadow nodes to color nodes 
  10a53b4... gl renderer: Cache current scale in RenderOpBuilder
  daa6e62... testsuite: Add an inset shadow rendering test case
  68dbc00... opbuffer: Remove unused op member
  7d203b7... gl renderer: Remove unused uniform from inset shadow shader
  c96c36a... gl renderer: Implement blurred inset shadow nodes

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