ztree中渲染的树，只在特殊节点显示checkbox复选框，或radio单选框

var treeNodes = [
	{ "id":1, "name":"test1", "nocheck":true},
	{ "id":2, "name":"test2"},
	{ "id":3, "name":"test3"}
]

//只需要在树节点设置nocheck：true就ok