Created by: zeffii
this attempts to employ a context manager approach to skipping tree updates in our socket ulity functions
- replace_socket
- multi_socket
- changeable_socket
the reason is that the context manager approach should certainly return the node_tree.skip_tree_update to the appropriate state, even if there's an exception mid function.
whether this is more readable, is up for debate.. but it's more pythonic, and it's what we should be doing for the sverchok state-machine anyway..