Fix printing of 64-bit quantities.

Do *NOT* assume that "%l[doxu]x" - or "%ll[doxu]" - is the way to print
a 64-bit quantity; on UN*X, it might be a "long" or a "long long",
depending on whether you're on a 32-bit or 64-bit platform and, on
Windows with MSVC++, it's not a long (even in 64-bit mode) and doesn't
use "%ll[doxu]", either.  Instead, use PRI[doxu]64; that's what C99
defines, and what we define ourselves if the C environment doesn't
define it.
diff --git a/print-forces.c b/print-forces.c
index 8384875..ec11635 100644
--- a/print-forces.c
+++ b/print-forces.c
@@ -1016,7 +1016,7 @@
 	if (vflag >= 1) {
 		printf("\n\tForCES Version %d len %uB flags 0x%08x ",
 		       ForCES_V(fhdr), mlen, flg_raw);
-		printf("\n\tSrcID 0x%x(%s) DstID 0x%x(%s) Correlator 0x%lx",
+		printf("\n\tSrcID 0x%x(%s) DstID 0x%x(%s) Correlator 0x%" PRIx64,
 		       ForCES_SID(fhdr), ForCES_node(ForCES_SID(fhdr)),
 		       ForCES_DID(fhdr), ForCES_node(ForCES_DID(fhdr)),
 		       EXTRACT_64BITS(fhdr->fm_cor));