diffs: seperate visually diff pills for better readability

rhodecode/public/css/code-block.less

@@ -745,12 +745,14 b' input.filediff-collapse-state {'
         opacity: .8;
         &:first-child {
             border-radius: @border-radius 0 0 @border-radius;
+            margin-right: 3px;
         }
         &:last-child {
             border-radius: 0 @border-radius @border-radius 0;
         }
         &:only-child {
             border-radius: @border-radius;
+            margin-right: 0;
         }
     }
 }