On occasion there is a 1-pixel space between some slices of a border-image. May be a rounding error.
See testcase from forum topic http://css3pie.com/forum/posting.php?mode=reply&f=3&t=70
Test case committed as tests/submitted/forum-f3-t70.html
Change border-image renderer to use simple shapes with an image fill …
…rather than rects with imagedata. This prevents the images from sometimes not getting painted after a long load, and fixes the issue with gaps sometimes appearing between slices.