Removed support for 40 column display from the apple2enh build. The startup code now switches to 80 column display itself. This allows to:

- configure the web browser to a 76 column wide display.
- get rid of some ugly special background handling code.

Note: The Applesoft wrapper program is now simply used to switch between the result of the apple2 build and the apple2enh build.
diff --git a/contiki-apple2/lib/crt0.S b/contiki-apple2/lib/crt0.S
index d923d80..1457b65 100644
--- a/contiki-apple2/lib/crt0.S
+++ b/contiki-apple2/lib/crt0.S
@@ -72,6 +72,10 @@
 
 .else
 
+	; Switch to 80 column mode
+	lda	#$00
+	jsr	$C300
+
 	; Get IRQ vector from ROM
 	lda	$FFFE
 	ldx	$FFFF