small improvements, added new command hf mf sniff (there will be cool sniffer). But now... here is optimized hf 14a snoop. As I see it works the same as th old version.

armsrc/appmain.c

@@ -761,6 +761,11 @@ void UsbPacketReceived(uint8_t *packet, int len)
 		case CMD_MIFARE_EML_CGETBLOCK:
 			MifareCGetBlock(c->arg[0], c->arg[1], c->arg[2], c->d.asBytes);
 			break;
+			
+		// mifare sniffer
+		case CMD_MIFARE_SNIFFER:
+			SniffMifare();
+			break;
 #endif
 
 #ifdef WITH_ICLASS