(libnfc-less-bitutils-more-ponies) Get rid of bitutils.[hc] (part 1).

- New API function append_iso14443a_crc();
  - Add a PRINT_HEX macro for driver debugging (replaces print_hex function from bitutils.c);
  - Move bit-mirroring related functions to libnfc/mirror-subr.[hc];
  - Move iso14443 related functions to libnfc/iso14443-subr.c;
  - Move libnfc/bitutils.c hex-dumping code to examples/nfc-utils.c;
  - Replace calls to swap_endian32() and swap_endian64() functions with calls to bswap32() and bswap64 provided by endian.h.

And while I am here:
  - Fix the DBG macro so that it does not throw warning at compile time.

include/nfc/nfc-messages.h

@@ -31,7 +31,10 @@
 // Useful macros
 #ifdef DEBUG
 //   #define DBG(x, args...) printf("DBG %s:%d: " x "\n", __FILE__, __LINE__,## args )
-  #define DBG(x, ...) fprintf(stderr, "DBG %s:%d: " x "\n", __FILE__, __LINE__, ## __VA_ARGS__ )
+  #define DBG(...) do { \
+    warnx ("DBG %s:%d", __FILE__, __LINE__); \
+    warnx ("    " __VA_ARGS__ ); \
+  } while (0)
 #else
   #define DBG(...) {}
 #endif

include/nfc/nfc.h

@@ -84,6 +84,7 @@ NFC_EXPORT const char* nfc_device_name(nfc_device_t* pnd);
 
 /* Misc. functions */
 NFC_EXPORT void iso14443a_crc(byte_t* pbtData, size_t szLen, byte_t* pbtCrc);
+NFC_EXPORT void append_iso14443a_crc(byte_t* pbtData, size_t szLen);
 NFC_EXPORT const char* nfc_version(void);
 
 #ifdef __cplusplus