code: function deleteMetadataForEntry(self, key) {
  			var iIndex = self._metadata.__byKey__[key];
  			delete self._metadata.__byKey__[key];
  			delete self._metadata.__byIndex__[iIndex];
  			seekMetadataLRU(self);
  		}
docs: Deletes all metadata for given key
  @param self the instance
  @param key the key for the entry