Add alt code to 2006/toledo2

The alt code is based on the author's remarks that should allow users
with non-standard systems like DOS/Windows which have conio.h to use
this program, replacing read(2) and write(2) syscalls. It need hardly be
mentioned that I have no way of testing this so it's possible I did
something wrong but it seems not the case (whether anything has changed
since 2006 that might also break it is unknown).

The bug status has been updated both that one bug is not actually a bug
but appeared to be a typo and there also appears to be a missing file
(IMPORT.COM).

2006/toledo2/Makefile

@@ -116,8 +116,8 @@ OBJ= ${PROG}.o
 DATA= C.BASIC C.BIOS
 TARGET= ${PROG} C
 #
-ALT_OBJ=
-ALT_TARGET=
+ALT_OBJ= ${PROG}.alt.o
+ALT_TARGET= ${PROG}.alt
 
 
 #################
@@ -144,6 +144,9 @@ C: C.BASIC
 alt: data ${ALT_TARGET}
 	@${TRUE}
 
+${PROG}.alt: ${PROG}.alt.c
+	${CC} ${CFLAGS} $< -o $@ ${LDFLAGS}
+
 # data files
 #
 data: ${DATA}