This function removes the item corresponding to the given key.
If there is no item with the given key in the first place, that is still counted as a success.
removeItem( key, successCallback, errorCallback )
| Name | Type | Description | 
| key | String | The key of the item to remove.If null or undefined is passed, "null" is used. | 
| successCallback | sap.EncryptedStorage~successCallback | If successful, the successCallback is invoked with no parameters. | 
| errorCallback | sap.EncryptedStorage~errorCallback | If there is an error, the errorCallback is invoked with an ErrorInfo object as the parameter. | 
var store = new sap.EncryptedStorage("storeName", "storePassword");
var successCallback = function() {
   alert("Value removed");
}
var errorCallback = function(error) {
   alert("An error occurred: " + JSON.stringify(error));
}
store.removeItem("somekey", successCallback, errorCallback);