fix some small issue (e.g: isCancel parameter in beforeRename & onRename;  Demo: async_edit.html)
no message
modify the wrong word about demo.
fix issue about : If some node's <a> tag has custom dom and this dom hasn't id, so drag the other node to this node's custom dom will can't drag to this node.
fixed issue about : the package 'exhide' will cause the node's 'isLastNode'  is wrong value.
v3.5.15 released
recovery demo
Merge remote-tracking branch 'remotes/zTree-original/master'