[ref #904] added 4 positions for corner icons

src/definitions/elements/icon.less

@@ -469,6 +469,30 @@ i.icons .corner.icon {
   font-size: @cornerIconSize;
   text-shadow: @cornerIconShadow;
 }
+i.icons .top.right.corner.icon {
+  top: 0;
+  left: auto;
+  right: 0;
+  bottom: auto;
+}
+i.icons .top.left.corner.icon {
+  top: 0;
+  left: 0;
+  right: auto;
+  bottom: auto;
+}
+i.icons .bottom.left.corner.icon {
+  top: auto;
+  left: 0;
+  right: auto;
+  bottom: 0;
+}
+i.icons .bottom.right.corner.icon {
+  top: auto;
+  left: auto;
+  right: 0;
+  bottom: 0;
+}
 
 i.icons .inverted.corner.icon {
   text-shadow: @cornerIconInvertedShadow;