Merge branches 'master' and 'private_key_qr_and_csv_export'
SPW now generates addresses first. Then gives the user the to option to enter their own private keys. It then validates and creates the paper wallet for printing
Small cleanup to code
Merge branches 'own_key_option' and 'own_keys' into own_key_option
Merge pull request #4 from nieldlr/own_key_option

Give user option to input own private keys