add 'pixel-perfect' 24x24px twins
gimp-info
gimp-user-manual
gimp-video


all current 24px icons from scalable icons-themes have now
'pixel-perfect' 24px vector twins.

Next step would be 'port' all remaining 22x22px icons to 24x24
(so 22x22 can be deprecated in future builds). As gimp refuses to use
24px for these icons, the 22px icons have to stay until gimp is ready for 24px.