interactive filtering "delete" node option should remove node only and not connecting nodes from filter

[mjsduncan]

after activating interactive filtering of a node with right-click "filter", a second right-click on a filtered node gives an option to delete the node, which also deletes the nodes connected to it. it would enhance the graph editing interface if only the selected node was deleted. this would permit searching the neighborhood of a node and then removing the undesired neighbors, and let the user "walking the graph" from link to link by hand. this could replace the current behavior of the "delete" function or be another option: "delete node", and "delete node and neighbors".

[mjsduncan]

to clarify, the bug is the random change in zoom level and position that happens when the "delete" option is invoked.

[mjsduncan]

thanks, abdulrahman!