Add ccsym to tools to determine OS/compiler specific symbols

Change BSD44_derived to __FreeBSD__ in numutils.c (need to know what
NetBSD is referred to as...someone?)

src/tools/ccsym

@@ -0,0 +1,12 @@
+#!/bin/sh
+/bin/cat >tmp.c <<EOF
+extern int foo;
+EOF
+for i in `cc -v -c tmp.c 2>&1`
+do
+        case "$i" in
+        -D*) echo "$i" | /usr/bin/sed 's/^-D//';;
+        -A*) /bin/test "2.7.2.1" && echo "$i" | /usr/bin/sed 's/^-A\(.*\)(\(.*\))/\1=\2/';;
+        esac
+done
+/bin/rm -f try.c