pal: Use __STDC_VERSION__ if config.h is not being used

So in the absence of configure tests we assume copysign() is
available if __STDC_VERSION__ indicates we are using c99.

component.xml

@@ -3,7 +3,7 @@
 <!-- component.xml.  Generated from component.xml.in by configure. -->
 
 <component id="pal" support="S">
-  <version>0.1.2</version>
+  <version>0.1.3</version>
   <path>libraries/pal</path>
   <description>Position Astronomy Library</description>
   <abstract><p>

configure.ac

@@ -2,7 +2,7 @@ dnl    Process this file with autoconf to produce a configure script
 AC_REVISION($Revision: 27534 $)
 
 dnl    Initialisation: package name and version number
-AC_INIT(pal, 0.1.2, [email protected])
+AC_INIT(pal, 0.1.3, [email protected])
 
 dnl    Require autoconf-2.50 at least
 AC_PREREQ(2.50)

palDfltin.c

@@ -62,6 +62,8 @@
 *        Initial version based on strtod
 *     2012-06-21 (TIMJ):
 *        Provide a backup for missing copysign.
+*     2012-06-22 (TIMJ):
+*        Check __STDC_VERSION__
 *     {enter_further_changes_here}
 
 *  Copyright:
@@ -89,14 +91,23 @@
 *-
 */
 
-#if HAVE_CONFIG_H
-#include <config.h>
-#endif
-
 /* Shenanigans for isblank() which is C99 only */
 #define _POSIX_C_SOURCE 200112L
 #define _ISOC99_SOURCE
 
+/* Use the config file if we have one, else look at
+   compiler defines to see if we have C99 */
+#if HAVE_CONFIG_H
+#include <config.h>
+#else
+#ifdef __STDC_VERSION__
+#  if (__STDC_VERSION__ >= 199901L)
+#    define HAVE_COPYSIGN 1
+#  endif
+#endif
+#endif
+
+/* System include files */
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>

palPertue.c

@@ -153,6 +153,8 @@
 *        Initial version direct conversion of SLA/F.
 *     2012-06-21 (TIMJ):
 *        Support a lack of copysign() function.
+*     2012-06-22 (TIMJ):
+*        Check __STDC_VERSION__
 *     {enter_further_changes_here}
 
 *  Copyright:
@@ -180,8 +182,16 @@
 *-
 */
 
+/* Use the config file if we have one, else look at
+   compiler defines to see if we have C99 */
 #if HAVE_CONFIG_H
 #include <config.h>
+#else
+#ifdef __STDC_VERSION__
+#  if (__STDC_VERSION__ >= 199901L)
+#    define HAVE_COPYSIGN 1
+#  endif
+#endif
 #endif
 
 #include <math.h>