New verion from previous work in Neustar GitLab
Make all elements visible by default. Refine instruction bolding
Redesign freeze buttons and refine freeze functions
Press F to fix/unfix a node. Refine fix mechanism: single nodes are fixed by default
Refine getDrawData algorithm to support cycles in the graph.
Redesign UI Style
Remove the test data
Refine the help page ui te match the main page style
Change scale extent to 0.01~10
Add indicate for nodes fixed by user
Refined search box with green and light gray style
Remove old library
Merge pull request #1 from zhangjn1991/private

New version with re-structured code and a bunch of new features:
- Folding of sub-graphs
- Search function
- Many UI improvements (zooming, repositioning etc.)