Fix fix on 1990/dds + make it use fgets()

The Makefile had -include stdio.h which made it fail to compile under
macOS (mismatch type of fopen()). I removed the prototype in the code.

I also made it use fgets() instead of gets() to make it safer.

1990/dds/LANDER.BAS

@@ -1,6 +1,6 @@
 10 REM Lunar Lander
 20 REM By Diomidis Spinellis
-30 PRINT "You aboard the Lunar Lander about to leave the spacecraft."
+30 PRINT "You board the Lunar Lander about to leave the spacecraft."
 60 GOSUB 4000
 70 GOSUB 1000
 80 GOSUB 2000