Added ability to:
 - close crashed databse (this removes listing from js only, since the database was never properly opened in the native code
 - delete database from local file system (this can be done by terminating an open database or by specifying the name of the database that you wish to delete, both methods call the same method in the native iOS code)
 - open an encrypted database using sqlcipher for iOS (see sqlcipher.net for more details on this, it should still be possible to connect to an unencrypted database while using the sqlite library too)