Make movement types optional in cameracontroller
Make movement types optional in cameracontroller

3D paths with only two key points are also supported now.
This means the following will be possible:

```
{
  "startFrame": 100,
  "endFrame": 1000,
  "points": [
    [1,2,3],
    [4,5,6],
    [7,8,9]
  ]
}
...
{
  "startFrame": 100,
  "endFrame": 1000,
  "points": [1,2,3]
}
...
{
  "startFrame": 100,
  "endFrame": 1000,
  "points": [
    [1,2,3],
    [4,5,6]
  ]
}
```

In addition, 3D paths may now follow a circle instead of a spline:

```
{
  "startFrame": 100,
  "endFrame": 1000,
  "type": "circle",
  "center": [0, 0, 0],
  "radius": 100
}
```

Thus concludes this commit message. The wiki will explain the format in
more detail.

ninjadev/nin,ninjadev/nin,ninjadev/nin