GTK3:
Support linked entries on primary toolbars
Use stock GTK style for expanders
Make progressbar colors darker in backdrop
Fix insensitive state of OSD scales and buttons
Fix a minor glitch in spinbuttons in RTL mode
Fix some glitches in header bar style
Fix content view checkboxes in backdrop
Remove special case of Nautilus pathbar buttons
GTK2:
Fix white border around background when overridden
Fix a regression in Chrome/Chromium toolbar drawing
WM:
Fix centering of the window title
