Fix build with GCC-4.5

http://gnudatalanguage.cvs.sourceforge.net/viewvc/gnudatalanguage/gdl/src/math_utl.hpp?r1=1.4&r2=1.5&view=patch
http://bugs.gentoo.org/show_bug.cgi?id=334415
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=564994

--- src/math_utl.hpp
+++ src/math_utl.hpp
@@ -22,11 +22,12 @@
 
 //#define ABS(xxx) (( xxx > -xxx)?(xxx):(-xxx))
 
-template< typename T>
-inline T abs( T a) { return (a>=T(0))?a:-a;}
-
 namespace lib {
 
+  // SA: needs to be inside a namespace for GCC 4.5
+  template< typename T>
+  inline T abs( T a) { return (a>=T(0))?a:-a;}
+
 //   int trans513(char *, int, int, int, DType);
 //   int transpose(char *, SizeT, SizeT [], SizeT, DType);
 //   int transpose_perm(char *, SizeT, SizeT [], SizeT, DType, long []);