Merge pull request #1612 from MITx/victor/fix-genex-css

remove links to missing image files.  We can add them if needed later.

common/static/js/capa/genex/genex.css

@@ -57,15 +57,10 @@ pre, #dna-strand {
   background: white;
 }
 .gwt-DialogBox .dialogBottomCenter {
-  background: url(images/hborder.png) repeat-x 0px -2945px;
-  -background: url(images/hborder_ie6.png) repeat-x 0px -2144px;
 }
 .gwt-DialogBox .dialogMiddleLeft {
-  background: url(images/vborder.png) repeat-y -31px 0px;
 }
 .gwt-DialogBox .dialogMiddleRight {
-  background: url(images/vborder.png) repeat-y -32px 0px;
-  -background: url(images/vborder_ie6.png) repeat-y -32px 0px;
 }
 .gwt-DialogBox .dialogTopLeftInner {
   width: 10px;
@@ -87,20 +82,12 @@ pre, #dna-strand {
   zoom: 1;
 }
 .gwt-DialogBox .dialogTopLeft {
-  background: url(images/circles.png) no-repeat -20px 0px;
-  -background: url(images/circles_ie6.png) no-repeat -20px 0px;
 }
 .gwt-DialogBox .dialogTopRight {
-  background: url(images/circles.png) no-repeat -28px 0px;
-  -background: url(images/circles_ie6.png) no-repeat -28px 0px;
 }
 .gwt-DialogBox .dialogBottomLeft {
-  background: url(images/circles.png) no-repeat 0px -36px;
-  -background: url(images/circles_ie6.png) no-repeat 0px -36px;
 }
 .gwt-DialogBox .dialogBottomRight {
-  background: url(images/circles.png) no-repeat -8px -36px;
-  -background: url(images/circles_ie6.png) no-repeat -8px -36px;
 }
 * html .gwt-DialogBox .dialogTopLeftInner {
   width: 10px;