Support storeNames with dashes in all drivers & methods

The storeName is only normalized inside the config() method. As a result:

• using createInstance() doesn't use the normalization method.
• dropInstance in websql isn't working for storeNames with spaces & dashes.
  • if we do the same normalization in there, then we will not be able to drop storeNames that contain dashes, eg local-forage-detect-blob-support
  • an other interesting Safari issue to keep in mind is #247