GitHub issues 78 79 81 num aff flags off by one (#82)

* Make sure all followers are free'd before freeing the character list

Otherwise, the followers structs will point to free'd memory and
the stop_follower call will attempt to dereference a free'd
characters' followers list.

* https://github.com/tbamud/tbamud/issues/79 typo

* https://github.com/tbamud/tbamud/issues/81 nullpointer crash on syntax check run

* NUM_AFF_FLAGS fix.

Now, consistently, the NUM_AFF_FLAGS is used in the same way as other
NUM_* variables. Specifically, the the number is consistent with
how others are defined - 1 above the highest in the list.

I would like to have removed the need to start from 1 instead of 0
as well, but the loading mechanism, and thus potentially a lot of
existing object files, use 0 as a marker for "no flags set", and
we can't easily fix that. So, the places we loop through the list,
we still need to make sure we're stying within the [1;NUM_AFF_FLAGS) interval.

Simultaneously, I've checked over the other flags, and it seems like
the usage is pretty consistent there.

Fixes https://github.com/tbamud/tbamud/issues/78

src/spec_procs.c

@@ -60,7 +60,7 @@ void sort_spells(void)
 static const char *how_good(int percent)
 {
   if (percent < 0)
-    return " error)";
+    return " (error)";
   if (percent == 0)
     return " (not learned)";
   if (percent <= 10)