[oozie] Add 3rd node to a fork
[oozie] Fix bug in Node.set_link
[oozie] Delete from more than 3 nodes in a Fork
[oozie] Hide extra dropping target right after fork and before join
[oozie] Add a node on top of node in a Fork
[oozie] Add a node below a Join
[oozie] Add a node on top of Fork
[oozie] Enable drop on the side of a fork and disable it on the side of joins