Revert "a different attempt at asynchronous hashcash token minting"

This reverts commit ec6b24f946e13230a4eee4c5513a3c3fa71e0ade.
Revert "get the hashcash token minted asynchronously. possible issue with opera. requires html5"

This reverts commit a4c85425d76bca57ee33697f174c9d8e74725d08.