work towards quote mode in MEGA65 screen editor

src/kernal/screen_m65/mega65_screen_quote.s

@@ -0,0 +1,23 @@
+
+// #LAYOUT# M65 KERNAL_1 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+//
+// CHROUT routine - screen support, control codes in quote mode, MEGA65 native mode version
+//
+
+
+m65_chrout_screen_quote:
+
+	// Low control codes are just +$80
+	clc
+	adc #$80
+
+	// If it overflowed, then it is a high control code,
+	// so we need to make it be $80 + $40 + char
+	// as we will have flipped back to just $00 + char, we should
+	// now add $c0 if C is set from overflow
+	bcc !+
+	adc #$BF    // C=1, so adding $BF + C = add $C0
+!:	
+	jmp m65_chrout_screen_literal