using namespace std; needed in tagdemo

[Peter O'Gorman]

Hi,

I decided to run "make check" on darwin with xlc++ as CXX and xlc as CC, all 
the C tests passed fine, I guess I never tested c++ before (oops!) as 
tagdemo fails. main.cpp and foo.cpp need a "using namespace std;" or need to 
change cout to std::cout and endl to std::endl.

Problem is that I'm not sure if/how this change will affect older compilers.

Thoughts? Answers?

Peter