ux: remove position relative on diff td as it causes very slow

rendering in browsers

rhodecode/public/css/diff.less

@@ -6,7 +6,8 b' div.diffblock .code-header .changeset_he'
 // Line select and comment
 div.diffblock.margined.comm tr {
     td {
-        position: relative;
+        // IMPORTANT - never position:relative this as it causes insanely
+        // slow rendering
     }
 
     .add-comment-line {
@@ -23,9 +24,8 b' div.diffblock.margined.comm tr {'
 
             a {
                 display: none;
-                position: absolute;
-                top: 2px;
-                left: 2px;
+                margin-top: 2px;
+                margin-left: 2px;
                 color: @grey3;
             }
         }

rhodecode/public/css/main.less

@@ -27,7 +27,6 b''
 @import 'panels';
 @import 'deform';
 
-
 //--- BASE ------------------//
 .noscript-error {
     top: 0;