[gtk] (10 commits) Non-fast-forward update to branch matthiasc/css-values

[Matthias Clasen <matthiasc src gnome org>]

The branch 'matthiasc/css-values' 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:

  2cb5d6d... css: Use a singleton for builtin image values
  598fb19... dimension: Improve the coverage of singletons

Commits added to the branch:

  77d9ae1... csscolorvalue: Don't resolve literal color values (*)
  bdd1c3f... csscolorvalue: Compute alpha/shade/mix of color literals di (*)
  e14b11b... cssvalue: Add type names for all classes (*)
  8c172f7... cssarrayvalue: Loosen the definition of "array value" (*)
  0e07516... cssarrayvalue: Reserve 2 pointers when parsing array values (*)
  41c456a... csscornervalue: Accept other values if x == y (*)
  160b104... cssnumbervalue: Add early-outs to transition code (*)
  7e7b2d6... css: Use a singleton for builtin image values
  790c0b0... dimension: Improve the coverage of singletons
  0e6be85... Add opaque black singleton

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