[ ] Enforce valid parameters.
    Some functions will cause a crash when called with invalid parameters (e.g.
    mifare_classic_authenticate() with a NULL key).
[ ] MAD and MifareApplication functions are tied to mifare_clasic_* ones and
    some refactoring is required to have a consistent API.
[ ] The DESFIRE_TRANSCEIVE macro should be replaced by a function
    DESFIRE_TRANSCEIVE was originaly a macro to enclose a nfc_initiator_trans-
    ceive_bytes() call with debug lines.  The functions has unexpectedly grown
    up and is now between 25 and 100 lines of code (depending of my refactoring
    mood).  The main drawbacks are poor readability, redundant code in the
    binary, debuggers don't cope well with macros, and by design it sucks.
[ ] Refactor examples and have consistent behavior.
    Dump to stdout unless -o is specified;
    Read from stdin unless a file is specified;
    Humanize dumps with a -h flag;
    Target aquisition is the same in all examples;