DESIGN-4160 feat: 复选树节点，某一个节点支持灰化，复选框也灰化，并且前边的展开收起是正常的

即disabled属性不再限制展开收起

src/case/ztree/0.treeview.js

@@ -225,16 +225,10 @@ BI.TreeView = BI.inherit(BI.Pane, {
         }
 
         function onExpand(event, treeId, treeNode) {
-            if (treeNode.disabled) {
-                return false;
-            }
             treeNode.halfCheck = false;
         }
 
         function onCollapse(event, treeId, treeNode) {
-            if (treeNode.disabled) {
-                return false;
-            }
         }
 
         return setting;

src/case/ztree/1.asynctree.js

@@ -104,9 +104,6 @@ BI.AsyncTree = BI.inherit(BI.TreeView, {
         }
 
         function beforeExpand(treeId, treeNode) {
-            if (treeNode.disabled) {
-                return false;
-            }
             self._beforeExpandNode(treeId, treeNode);
         }
 
@@ -118,16 +115,10 @@ BI.AsyncTree = BI.inherit(BI.TreeView, {
         }
 
         function onExpand(event, treeId, treeNode) {
-            if (treeNode.disabled) {
-                return false;
-            }
             treeNode.halfCheck = false;
         }
 
         function onCollapse(event, treeId, treeNode) {
-            if (treeNode.disabled) {
-                return false;
-            }
             treeNode.halfCheck = false;
         }