Merge pull request #129 from GordonSmith/ShowHideEdges

Add ability to show/hide the edges.
Merge pull request #130 from GordonSmith/SnapToGrid

Add snap to grid for graph.
Refactor "pos" to not automatically update.

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Demo/Test Page(s)

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>