OO-703 add config options to shift menu tree depending on opener size and position

src/main/webapp/static/themes/openolat/all/_definitions.scss

@@ -65,6 +65,8 @@ $main_shadow_color : #D3D3D3 !default;
 $tree_level_margin : 1em !default;
 $tree_padding_steps_px : 0 !default; /* alternate solution to tree_level_margin in case the tree link has block layout */
 $tree_padding_opener_px : 13px !default; /* total width of opener image (actual image width + whitespace) */
+$tree_padding_opener_left_px : 1px !default; /* left position of opener image */
+$tree_padding_opener_top_px : 0px;
 /* show or hide tree icons, if yes, width of icons */
 $tree_show_icons : true !default; 
 $treeicon_width_px : 20px !default;

src/main/webapp/static/themes/openolat/all/modules/_nav.scss

@@ -160,8 +160,8 @@ div.b_tree {
 			
 			.b_tree_oc_l0 {
 				position: absolute;
-				top: 0px;
-				left: 0px;
+				top: $tree_padding_opener_top_px;
+				left: $tree_padding_opener_left_px;
 				z-index: 9;
 			}
 			
@@ -177,7 +177,7 @@ div.b_tree {
 			/*  icon positioning */
 			@for $i from 1 through 11 {
 				.b_tree_oc_l#{$i}  { 
-					position:absolute; top:0px; left: 1px + ($i * $tree_padding_steps_px); 
+					position:absolute; top:$tree_padding_opener_top_px; left: $tree_padding_opener_left_px + ($i * $tree_padding_steps_px); 
 					z-index:9; 
 				}