Second part of error handling.

- Define two sets of DE<FOOBAR> macros: the first one for 'generic' errors
  which could be encountered regardless of the NFC device the library is acting
  with (0xX000), and ont set for device-dependant errors (0x0X00).
- Make some more functions accept a nfc_device_t* as first argument to have
  access to the iLastError;
- Reset errors when entering public API functions;
- Save errors when applicable;
- Distinguish system-level errors (e.g. I/O error) and operational errors (the
  PCD returns an unexpected value);
- Minor tweaks.

Update issue 65
Status: Feedback

New review:
Owner: rconty@il4p.fr
Cc: rtartiere@il4p.fr
Summary: Review the error-handling code.
Branch: /branches/libnfc-error-handling

For this development, a strong emphasis has been set on making changes that
will not go through our way on the way to libnfc-1.6+.  For this reason, some
constructs are not natural (e.g. error codes defined in two different places),
please keep this in mind when reviewing.

libnfc/chips/pn53x.h

@@ -69,6 +69,11 @@
 #define RFCI_ANALOG_TYPE_B          0x0C //  3
 #define RFCI_ANALOG_TYPE_14443_4    0x0D //  9
 
+/* PN53x specific device-level errors */
+#define DENACK          0x0100        /* NACK */
+#define DEACKMISMATCH   0x0200        /* Unexpected data */
+#define DEISERRFRAME    0x0300        /* Error frame */
+
 bool pn53x_transceive_callback(nfc_device_t* pnd, const byte_t *pbtRxFrame, const size_t szRxFrameLen);
 bool pn53x_transceive(nfc_device_t* pnd, const byte_t* pbtTx, const size_t szTxLen, byte_t* pbtRx, size_t* pszRxLen);
 byte_t pn53x_get_reg(nfc_device_t* pnd, uint16_t ui16Reg);