Arnitech controller: the TOD set at boot, and a jump table at $FF00

A new option, ARNITECH_CONTROLLER, on in the mc64 configuration only.
IOINIT starts timer A with CIA #1's TOD on 50 Hz, the mc64's mains, and
if the Arnitech controller's signature "ARNI" is at $DE80, latches its
clock and copies its real time into the TOD, hours first and tenths
last, flipping bit 7 of an hour of 12 first, since the CIA flips it
back when 12 is written. Without the signature the TOD is left alone.

The Arnitech jump table at $FF00: "ARNI", version $01, two entries, and
JMPs from $FF06: $FF06 finds the first Card slot holding a Card of the
type in A (carry clear, the slot in A, its Card window's low byte in
X; carry set if none or no controller), $FF09 sets the TOD as IOINIT
does. $FF48-$FF80 stay clear. The code is in new files under
src/kernal/arnitech; other configurations build as before.

src/,,config_mc64.s

@@ -10,6 +10,8 @@
 ; Same as the 'c64' configuration, except:
 ; - the banner names mc64
 ; - BCD_SAFE_INTERRUPTS is off, for IRQ entry timing closer to the original
+; - ARNITECH_CONTROLLER: IOINIT sets CIA1's TOD on 50 Hz and from the Arnitech controller's clock,
+;   and the Arnitech jump table is at $FF00 (src/kernal/arnitech)
 
 
 
@@ -103,6 +105,7 @@
 ;; #CONFIG# TAPE_WEDGE                 NO
 ;; #CONFIG# TAPE_HEAD_ALIGN            NO
 ;; #CONFIG# BCD_SAFE_INTERRUPTS        NO
+;; #CONFIG# ARNITECH_CONTROLLER        YES
 
 
 ; --- BASIC features