bugfix: store list must not be empty (throws in Chrome 17)
bugfix: store list must not be empty (throws in Chrome 17)

GerHobbelt/IDBWrapper,mizchi/idb-wrapper-promisify,kilbot/IDBWrapper,rubenstolk/IDBWrapper,jayfunk/IDBWrapper,jayfunk/IDBWrapper,jensarps/IDBWrapper,kilbot/IDBWrapper,safetychanger/IDBWrapper,safetychanger/IDBWrapper,mizchi/idb-wrapper-promisify,rubenstolk/IDBWrapper,jensarps/IDBWrapper