NavMesh tools/libraries enhancements

[dbierek]

Adds Anthony Fuller's NavTool updates from #11:

This PR contains multiple improvements and changes to NavWeakness, NavTool, and NavViewer these are outlined below:

NavWeakness

• Switched to my NavPower header library
• Added functions to output the navmesh as human readable or for the viewer
• Changed the Surfaces object to Areas and changed the Unk02 object to KDTree

NavTool

• Added an option to output as a human readable format (--human)
• Changed the Surfaces object to Areas and changed the Unk02 object to KDTree

NavViewer

• Renamed Surfaces.js to NavMeshes.js
• Changed names of check boxes to match what they actually are
• Added rendering of k-d tree bounding boxes
• Now renders faces and edges by default instead of the "unknown points"
• Changed the Surfaces object to Areas and changed the Unk02 object to KDTree

.gitignore

• Removed unused Faces.js
• Changed Surfaces.js to NavMeshes.js
• Added .vscode and _build

Also adds new updates to enable:
Writing to NAVP
Writing to JSON
Reading from JSON

NavpJsonVersion 0.1
Example:

{
  "Areas": [
    {
      "Area": { "Index": 1 },
      "Edges": [
        {
          "Position": { "X": -22.8499, "Y": -12.9597, "Z": -1.3357 },
          "Flags": 662
        },
        {
          "Position": { "X": -21.75, "Y": -15.85, "Z": -1.3504 },
          "Flags": 451
        },
        {
          "Adjacent Area": 2,
          "Position": { "X": -20.75, "Y": -12.9497, "Z": -1.3505 },
          "Flags": 1772
        }
      ]
    },
    {
      "Area": { "Index": 2, "Type": "Steps" },
      "Edges": [
        {
          "Adjacent Area": 3,
          "Position": { "X": -20.75, "Y": -8.4714, "Z": 1.6817 },
          "Flags": 1776
        },
        { "Position": { "X": -22.5496, "Y": -8.48, "Z": 1.6943 } },
        { "Position": { "X": -22.85, "Y": -8.55, "Z": 1.65 } },
        {
          "Adjacent Area": 1,
          "Position": { "X": -22.8499, "Y": -12.9597, "Z": -1.3357 },
          "Flags": 1772
        },
        { "Position": { "X": -20.75, "Y": -12.9497, "Z": -1.3505 } }
      ]
    },
    {
      "Area": { "Index": 3, "Type": "Steps" },
      "Edges": [
        { "Position": { "X": -22.55, "Y": -8.25, "Z": 1.85 } },
        {
          "Adjacent Area": 2,
          "Position": { "X": -22.5496, "Y": -8.48, "Z": 1.6943 },
          "Flags": 1776
        },
        { "Position": { "X": -20.75, "Y": -8.4714, "Z": 1.6817 } },
        {
          "Position": { "X": -20.75, "Y": -6.45, "Z": 3.0503 },
          "Type": "Portal",
          "Flags": 594
        }
      ]
    }
  ],
  "NavpJsonVersion": "0.1"
}