map_update_response add fov

[Oipo]

Add calculated fov for the clients. Current suggestion for map_update_response:

{
  "npcs": [/* list of visible npcs here */]
  "x": /* x position of player */
  "y": /* y position of player */
  "fov": [] /* a 9x9 array of 0 or 1 values. Center of array indicates player position (see above), can extend beyond map boundaries as center is always player position. */
}

Example fov of a player standing on position (0, 0) of a map without obstacles:

111110000111110000111110000111110000111110000000000000000000000000000000000000000

Array access can be determined by x + y * 9.

[seiyria]

FoV should have these values:

0 - visible, no darkness
1 - semi-visible, darkness (this is if you can see in the dark, and the darkness spell is cast here)
2 - reserved
3 - actual fov blocking