Improvements/Fixes to 14443 sniffing/snooping

- fixed a circular buffer rollover bug in iso14443a.c
- fixed 7 Byte UID handling in hf mf sniff
- fixed "cannot append" error in hf mf sniff d
- fixed hint on mfkey32 in hf mf sim x
- fixed hf mf sniff sometimes showing rogue data from previous calloc
- improve snooping/sniffing by syncing modulation detector window with reader signal (hi_iso14443a.v)
- code cleanup of hi_iso14443a.v

armsrc/fpgaloader.c

@@ -115,11 +115,11 @@ void FpgaSetupSsc(void)
 	AT91C_BASE_SSC->SSC_RCMR = SSC_CLOCK_MODE_SELECT(1) | SSC_CLOCK_MODE_START(1);
 
 	// 8 bits per transfer, no loopback, MSB first, 1 transfer per sync
-	// pulse, no output sync, start on positive-going edge of sync
+	// pulse, no output sync
 	AT91C_BASE_SSC->SSC_RFMR = SSC_FRAME_MODE_BITS_IN_WORD(8) |	AT91C_SSC_MSBF | SSC_FRAME_MODE_WORDS_PER_TRANSFER(0);
 
 	// clock comes from TK pin, no clock output, outputs change on falling
-	// edge of TK, sample on rising edge of TK
+	// edge of TK, sample on rising edge of TK, start on positive-going edge of sync
 	AT91C_BASE_SSC->SSC_TCMR = SSC_CLOCK_MODE_SELECT(2) |	SSC_CLOCK_MODE_START(5);
 
 	// tx framing is the same as the rx framing