Remove irrelevant code and comments.

src/openseadragon.js

@@ -2899,10 +2899,7 @@ function OpenSeadragon( options ){
         promise.prototype.then = function () {
             throw "OpenSeadragon needs promises API. Your browser do not support promises. You can add polyfill.js to import promises.";
         };
-        promise.prototype.resolve = function () {
-            throw "OpenSeadragon needs promises API. Your browser do not support promises. You can add polyfill.js to import promises.";
-        };
-        promise.prototype.reject = function () {
+        promise.prototype.catch = function () {
             throw "OpenSeadragon needs promises API. Your browser do not support promises. You can add polyfill.js to import promises.";
         };
         promise.prototype.finally = function () {

src/tile.js

@@ -514,15 +514,6 @@ $.Tile.prototype = {
         });
     },
 
-    /**
-     * FIXME:refactor
-     * @return {boolean}
-     */
-    dataReady() {
-        return this.getCache(this.cacheKey).loaded;
-    },
-
-
     /**
      * Renders the tile in a canvas-based context.
      * @function

src/tilesource.js

@@ -892,7 +892,6 @@ $.TileSource.prototype = {
      * @deprecated
      */
     destroyTileCache: function (cacheObject) {
-        // FIXME: still allow custom desctruction? probably not - cache system should handle all
         $.console.error("[TileSource.destroyTileCache] has been deprecated. Use cache API of a tile instead.");
         //no-op, handled internally
     },
@@ -901,7 +900,7 @@ $.TileSource.prototype = {
      * Raw data getter, should return anything that is compatible with the system, or undefined
      * if the system can handle it.
      * @param {OpenSeadragon.CacheRecord} cacheObject context cache object
-     * @returns {*} cache data
+     * @returns {Promise<?>} cache data
      * @deprecated
      */
     getTileCacheData: function(cacheObject) {