Move top-level typedefs to typedefs.js

With one exception, those directly in the `ol` namespace can be moved without problem.
Some left-over goog.requires are also removed.

src/ol/tilecoord.js

@@ -1,19 +1,9 @@
-goog.provide('ol.TileCoord');
 goog.provide('ol.tilecoord');
 
 goog.require('goog.asserts');
 goog.require('ol.extent');
 
 
-/**
- * An array of three numbers representing the location of a tile in a tile
- * grid. The order is `z`, `x`, and `y`. `z` is the zoom level.
- * @typedef {Array.<number>} ol.TileCoord
- * @api
- */
-ol.TileCoord;
-
-
 /**
  * @enum {number}
  */