[gtk] (8 commits) Non-fast-forward update to branch device-timestamp

[Matthias Clasen <matthiasc src gnome org>]

The branch 'device-timestamp' 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:

  89409d9... gdk: Add gdk_device_get_timestamp
  33ba1c7... text: Use device timestamps for obscured cursors
  ba07227... textview: Use device timestamps for obscured cursors

Commits added to the branch:

  50b7029... clipboard: Fix a crash when GdkContentProviderUnion doesn't (*)
  cc64dba... Merge branch 'carlosgc/clipboard-crash' into 'master' (*)
  50d4209... Make testsuite fail if we lack pixbuf loaders (*)
  2496ab0... Be explicit when building gdk-pixbuf subproject (*)
  3014649... Merge branch 'pixbuf-loader-check' into 'master' (*)
  f131d68... gdk: Add gdk_device_get_timestamp
  cdfdf03... text: Use device timestamps for obscured cursors
  019855a... textview: Use device timestamps for obscured cursors

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