Add option to disable Rock-Ridge support --disable-rock

Add IS_ISSOCK() or S_ISLNK() macros for Rock-Ridge when environment
doesn't have it, e.g. MSYS 1.0.10 with MinGW 3.4.2.

Go over --enable settings. --disable-cpp-progs now works.

Require libcddb 1.0.1 or better

src/cd-info.c

@@ -1,5 +1,5 @@
 /*
-    $Id: cd-info.c,v 1.142 2005/07/03 23:14:23 rocky Exp $
+    $Id: cd-info.c,v 1.143 2005/09/15 06:36:01 rocky Exp $
 
     Copyright (C) 2003, 2004, 2005 Rocky Bernstein <rocky@panix.com>
     Copyright (C) 1996, 1997, 1998  Gerd Knorr <kraxel@bytesex.org>
@@ -443,9 +443,7 @@ print_cddb_info(CdIo_t *p_cdio, track_t i_tracks, track_t i_first_track)
   
     cddb_disc_destroy(p_cddb_disc);
     cddb_destroy(p_conn);
-#if LIBCDDB_VERSION_NUM >= 1
     libcddb_shutdown();
-#endif
   }
 }
 #endif