Merge pull request #2778 from Kondou-ger/optimize_pictures

core/css/images/ui-bg_diagonals-thick_18_b81900_40x40.png

core/css/images/ui-bg_diagonals-thick_20_666666_40x40.png

core/css/images/ui-bg_flat_100_ffffff_40x100.png

core/css/images/ui-bg_flat_10_000000_40x100.png

core/css/images/ui-bg_flat_35_1d2d44_40x100.png

core/css/images/ui-icons_1d2d44_256x240.png

core/css/images/ui-icons_222222_256x240.png

core/css/images/ui-icons_ffd27a_256x240.png

core/css/images/ui-icons_ffffff_256x240.png

core/img/actions/add.svg

core/img/actions/caret-dark.png

core/img/actions/caret-dark.svg

core/img/actions/caret.png

core/img/actions/caret.svg

core/img/actions/clock.png

core/img/actions/clock.svg

core/img/actions/close.png

core/img/actions/close.svg

core/img/actions/delete-hover.png

core/img/actions/delete-hover.svg