1. Set node to hide the checkbox or radio. It is valid when [setting.check.enable = true]
2. zTree support identification string 'true' & 'false'.
Default: false
true means: the node hide the checkbox or radio, and don't affect the checked association, and don't affect its parent node's half-checked status.
false means: the node show the checkbox or radio.
var nodes = [
{ "id":1, "name":"test1", "nocheck":true},
{ "id":2, "name":"test2"},
{ "id":3, "name":"test3"}
]