en #9 custom storage: delayed md5 calculation and storage WIP

- delayed sprite storage with promise queue
  WARNING: storage time is set artificially high to 1000ms
  WARNING: using artificially low MAX_STORAGE=3 number
- removed md5 from promise fieds, instead,
  final computation returns a dictionary with field 'md5'
- somewhat fixed BOTCH.testStoreSprite()
- commented mutant beetles from default-botch-sprites.js

src/extensions/botch/botch-storage-helper.js

@@ -176,6 +176,7 @@ class BotchStorageHelper extends Helper {
             name: name,
             parentId: parentId
         };
+        this.size += 1;
         return id;
     }
 

src/extensions/botch/default-botch-sprites.js

@@ -4,6 +4,11 @@
  * for now I just prepended 'Mutant'
  * @since botch-0.1
  */
+const DEFAULT_BOTCH_SPRITES = []
+
+/* TODO commenting Scratch stuff, instead we should put first organism in the tree, see
+        https://github.com/CoderDojoTrento/botch-gui/issues/14
+
 const DEFAULT_BOTCH_SPRITES = [
     {
         name: 'Mutant Beetle',
@@ -124,5 +129,6 @@ const DEFAULT_BOTCH_SPRITES = [
         }
     }
 ];
+*/
 
 module.exports = DEFAULT_BOTCH_SPRITES;