more DEF_PAGER

For Unix, add internal vs external pager choice to #version.
Others always use internal pagination so don't need to see that.

Also remove obsolete "command completion" option.  I don't know
when it became unconditional but that was long enough ago to be
absent from the git log and from second cvs log included in that.

And streamline the RNG seed stuff a bit.

src/mdlib.c

@@ -437,9 +437,6 @@ static const char *build_opts[] = {
     "console escape codes for tile hinting",
 #endif
 #endif
-#ifdef COM_COMPL
-    "command line completion",
-#endif
 #ifdef LIFE
     "Conway's Game of Life",
 #endif
@@ -504,20 +501,23 @@ static const char *build_opts[] = {
 #endif
 #endif
 #endif
+#ifdef UNIX
+#if defined(DEF_PAGER) && !defined(DLB)
+    "external pager used for viewing help files",
+#else
+    "internal pager used for viewing help files",
+#endif
+#endif /* UNIX */
     /* pattern matching method will be substituted by nethack at run time */
     "pattern matching via :PATMATCH:",
 #ifdef USE_ISAAC64
     "pseudo random numbers generated by ISAAC64",
 #ifdef DEV_RANDOM
-#ifdef NHSTDC
     /* include which specific one */
-    "strong PRNG seed available from " DEV_RANDOM,
-#else
-    "strong PRNG seed available from DEV_RANDOM",
-#endif
+    "strong PRNG seed from " DEV_RANDOM,
 #else
 #ifdef WIN32
-    "strong PRNG seed available from CNG BCryptGenRandom()",
+    "strong PRNG seed from CNG BCryptGenRandom()",
 #endif
 #endif  /* DEV_RANDOM */    
 #else   /* ISAAC64 */