Provide better debugger formatting for Vector3 components

[citizenmatt]

Vector2, Vector3, Quaternion, Rect, etc. specify a limit of 1 or 2 decimal places in the ToString output. Since ToString is used by the debugger, this can cause inaccurate values to be displayed, and confusion for the user.

The Unity plugin should be able to override the default display of these types to provide a more accurate view of the values.

Also check for other types that do this.