Improve performance of network graph
Created by: hiroponz
I think that loading network graph is as fast as that of 5.0.
Overview
- Rendering graph partially.
- Reduce database access to get notes.
- Enable vertical scrolling.Thanks @giggsey.
- Some minor bugs related to network graph is fixed.
Dragging network graph is disabled, because it conflicts with scroll.
Screenshot
fixes #3684 refs #3711