[vala] (8 commits) Non-fast-forward update to branch wip/glib-2-50

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'wip/glib-2-50' 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:

  38d7944... glib-2.0: Add new symbols for 2.50

Commits added to the branch:

  af03c0d... gobject-2.0: Fix binding of ParamSpec.get_default_value() (*)
  94acede... posix: Correct documentation comment for crypt() (*)
  e017c96... libxml-2.0: Fix 'htmlEncodeEntities' and 'UTF8ToHtml' using (*)
  28fa531... json-glib-1.0: Fix 'Json.Serializable' interface metadata (*)
  5d25a8c... vapi: Update GIR-based bindings (*)
  52f3661... gidlparser: Make sure to only handle the needed cairo symbo (*)
  0176ead... gtk+-3.0: Update to 3.21.4+0f329195 (*)
  69c938d... glib-2.0: Add new symbols for 2.50

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