[svn-r12180] Purpose: Maintenance

Description:
    Added alias H5_std so either the global or std namespace can be
    used, depending on H5_NO_STD.

Platforms tested:
    Linux 2.4 (heping)
    SunOS 5.8 64-bit (sol)
    AIX 5.1 (copper)

c++/examples/readdata.cpp

@@ -27,7 +27,6 @@
 
 #ifndef H5_NO_NAMESPACE
 #ifndef H5_NO_STD
-    using std::string;
     using std::cout;
     using std::endl;
 #endif  // H5_NO_STD
@@ -36,7 +35,8 @@
 #include "H5Cpp.h"
 
 #ifndef H5_NO_NAMESPACE
-using namespace H5;
+    using namespace H5;
+    using H5_std::string;
 #endif
 
 const string FILE_NAME( "SDS.h5" );