optimize / re-compress png images losslessly

[PeterDaveHello]

55 png images optimized losslessly using Google's zopflipng:

 addons/pager/icons/first.png                              | Bin 720 -> 642 bytes
 addons/pager/icons/last.png                               | Bin 737 -> 661 bytes
 addons/pager/icons/next.png                               | Bin 736 -> 658 bytes
 addons/pager/icons/prev.png                               | Bin 745 -> 663 bytes
 css/images/bootstrap-black-unsorted.png                   | Bin 284 -> 281 bytes
 css/images/bootstrap-white-unsorted.png                   | Bin 223 -> 180 bytes
 css/images/dragtable-handle.png                           | Bin 103 -> 75 bytes
 css/images/dropbox-asc-hovered.png                        | Bin 275 -> 200 bytes
 css/images/dropbox-asc.png                                | Bin 278 -> 204 bytes
 css/images/dropbox-desc-hovered.png                       | Bin 273 -> 195 bytes
 css/images/dropbox-desc.png                               | Bin 277 -> 206 bytes
 css/images/metro-black-asc.png                            | Bin 213 -> 161 bytes
 css/images/metro-black-desc.png                           | Bin 232 -> 172 bytes
 css/images/metro-unsorted.png                             | Bin 181 -> 151 bytes
 css/images/metro-white-asc.png                            | Bin 209 -> 168 bytes
 css/images/metro-white-desc.png                           | Bin 224 -> 179 bytes
 dist/css/images/bootstrap-black-unsorted.png              | Bin 284 -> 281 bytes
 dist/css/images/bootstrap-white-unsorted.png              | Bin 223 -> 180 bytes
 dist/css/images/dragtable-handle.png                      | Bin 103 -> 75 bytes
 dist/css/images/dropbox-asc-hovered.png                   | Bin 275 -> 200 bytes
 dist/css/images/dropbox-asc.png                           | Bin 278 -> 204 bytes
 dist/css/images/dropbox-desc-hovered.png                  | Bin 273 -> 195 bytes
 dist/css/images/dropbox-desc.png                          | Bin 277 -> 206 bytes
 dist/css/images/first.png                                 | Bin 720 -> 642 bytes
 dist/css/images/last.png                                  | Bin 737 -> 661 bytes
 dist/css/images/metro-black-asc.png                       | Bin 213 -> 161 bytes
 dist/css/images/metro-black-desc.png                      | Bin 232 -> 172 bytes
 dist/css/images/metro-unsorted.png                        | Bin 181 -> 151 bytes
 dist/css/images/metro-white-asc.png                       | Bin 209 -> 168 bytes
 dist/css/images/metro-white-desc.png                      | Bin 224 -> 179 bytes
 dist/css/images/next.png                                  | Bin 736 -> 658 bytes
 dist/css/images/prev.png                                  | Bin 745 -> 663 bytes
 docs/css/images/glyphicons-halflings-white.png            | Bin 8777 -> 8621 bytes
 docs/css/images/glyphicons-halflings.png                  | Bin 12799 -> 12586 bytes
 docs/css/images/ui-bg_diagonals-thick_90_eeeeee_40x40.png | Bin 312 -> 155 bytes
 docs/css/images/ui-bg_flat_15_cd0a0a_40x100.png           | Bin 206 -> 86 bytes
 docs/css/images/ui-bg_glass_100_e4f1fb_1x400.png          | Bin 350 -> 194 bytes
 docs/css/images/ui-bg_glass_50_3baae3_1x400.png           | Bin 336 -> 190 bytes
 docs/css/images/ui-bg_glass_80_d7ebf9_1x400.png           | Bin 346 -> 197 bytes
 docs/css/images/ui-bg_highlight-hard_100_f2f5f7_1x100.png | Bin 332 -> 176 bytes
 docs/css/images/ui-bg_highlight-hard_70_000000_1x100.png  | Bin 249 -> 120 bytes
 docs/css/images/ui-bg_highlight-soft_100_deedf7_1x100.png | Bin 387 -> 202 bytes
 docs/css/images/ui-bg_highlight-soft_25_ffef8f_1x100.png  | Bin 309 -> 159 bytes
 docs/css/images/ui-icons_2694e8_256x240.png               | Bin 4549 -> 3756 bytes
 docs/css/images/ui-icons_2e83ff_256x240.png               | Bin 4549 -> 3756 bytes
 docs/css/images/ui-icons_3d80b3_256x240.png               | Bin 4549 -> 3756 bytes
 docs/css/images/ui-icons_72a7cf_256x240.png               | Bin 4549 -> 3756 bytes
 docs/css/images/ui-icons_ffffff_256x240.png               | Bin 6299 -> 3756 bytes
 docs/css/select2.png                                      | Bin 613 -> 577 bytes
 docs/css/select2x2.png                                    | Bin 845 -> 743 bytes
 docs/img/external.png                                     | Bin 165 -> 140 bytes
 docs/img/grid-default-thumb.png                           | Bin 959 -> 924 bytes
 docs/img/link.png                                         | Bin 704 -> 498 bytes
 docs/img/screens-blue.png                                 | Bin 474 -> 473 bytes
 docs/img/screens.png                                      | Bin 495 -> 489 bytes

[Mottie]

Awesome thanks!