Fix 1985/applin under macOS

The solution is a curious one that I should have known. It wasn't even a
change in the code itself; rather in macOS one needs to include unistd.h
as with macOS without a proper prototype at least some functions do not
work right. This showed itself in 1984/anonymous as well though I had to
do a bit more to fix that one - provide a prototype in the code
(including the header file did not work - this was documented at one
point in the README.md and possibly bugs.md) and change the code
slightly as well. Ironically this was figured out through linux! See
bugs.md as I updated the on warnings section - this was an example entry
where some warnings are worth fixing.

1985/applin/Makefile

@@ -61,7 +61,7 @@ CDEFINE=
 
 # Include files that are needed to compile
 #
-CINCLUDE=
+CINCLUDE= -include unistd.h
 
 # Optimization
 #