In non-high-contrast mode, use background-color CSS for color swatches, rather than an image.  In high-contrast mode, make each color swatch contain an <img> node that loads the entire palette image, but scrolls/clips it to only show the color for that swatch.
In non-high-contrast mode, use background-color CSS for color swatches, rather than an image.  In high-contrast mode, make each color swatch contain an <img> node that loads the entire palette image, but scrolls/clips it to only show the color for that swatch.

This change avoids swatch/border alignment issues on webkit with a zoom setting, and alignment issues in other browsers, even when not zoomed, that started in 1.6, as seen in #12386.

Note that webkit never enters high contrast mode; even when the machine is set to high-contrast mode, the browser still displays background images.   So webkit will always using background-color CSS.

Fixes #3919, #10959, #12386 in trunk/ and 1.6/ branch, !strict.


git-svn-id: 674a2d6b1e32e53f607eb824547723f32280967e@23979 560b804f-0ae3-0310-86f3-f6aa0a117693

harbalk/delite,Sam-Cummins/delite,harbalk/delite,Sam-Cummins/delite,kitsonk/delite,kitsonk/delite