Clean up library dependencies

Move stuff to untangle the ugly cyclic dependencies between the
archives built for selected subdirectories of src/lib/:

* Move common/io.c to empthread/ because it requires empthread stuff

* Move parts of subs/nstr.c to common/nstreval.c to satisfy
  common/ef_verify.o

* Move getstarg.c getstring.c onearg.c from gen/ to subs/ because they
  require stuff from there

* Move bridgefall.c check.c damage.c empobj.c journal.c maps.c
  sectdamage.c from common/ to subs/ because they require stuff from
  there

* Move cnumb.c from subs/ to common/ to satisfy common/type.o

* Move log.c fsize.c from common/ to gen/ because they really belong
  there

* Move emp_config.c mapdist.c from gen/ to common/ because they really
  belong there, and require stuff from libglobal.a

Also package as/ as libas.a to satisfy common/path.o.

Remaining dependencies:

    lib             needs
    --------------------------------------------
    libas.a         libglobal.a
    libcommon.a     libas.a libglobal.a libgen.a
    libgen.a
    libglobal.a
    liblwp.a        libgen.a
    libw32.a[*]     libgen.a

    [*] Except for service.o, which can only be linked into the server

Link order now: liblwp.a libcommon.a libas.a libgen.a libglobal.a
libw32.a.  The position of libw32.a is not quite right, but works
anyway.

src/lib/gen/fsize.c

@@ -0,0 +1,80 @@
+/*
+ *  Empire - A multi-player, client/server Internet based war game.
+ *  Copyright (C) 1986-2008, Dave Pare, Jeff Bailey, Thomas Ruschak,
+ *                           Ken Stevens, Steve McClure
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *  ---
+ *
+ *  See files README, COPYING and CREDITS in the root of the source
+ *  tree for related information and legal notices.  It is expected
+ *  that future projects/authors will amend these files as needed.
+ *
+ *  ---
+ *
+ *  fsize.c: BSD dependant file and block sizing routines
+ * 
+ *  Known contributors to this file:
+ *     Dave Pare, 1986
+ *     Doug Hay, 1998
+ *     Steve McClure, 1998
+ */
+
+#include <config.h>
+
+#include <sys/stat.h>
+#include <unistd.h>
+#include "prototypes.h"
+
+/*
+ * return the size of the file in bytes.
+ */
+int
+fsize(int fd)
+{
+    struct stat statb;
+
+    if (fstat(fd, &statb) < 0)
+	return -1;
+    return statb.st_size;
+}
+
+/*
+ * Return the preferred block size for I/O on FD.
+ */
+int
+blksize(int fd)
+{
+#if defined(_WIN32)
+    return 2048;
+#else  /* !_WIN32 */
+    struct stat statb;
+
+    if (fstat(fd, &statb) < 0)
+	return 1024;
+    return statb.st_blksize;
+#endif /* !_WIN32 */
+}
+
+time_t
+fdate(int fd)
+{
+    struct stat statb;
+
+    if (fstat(fd, &statb) < 0)
+	return 0;
+    return statb.st_mtime;
+}