Clean up after standard literals patch.

[Jonathan Wakely]

On 7 June 2013 15:45, Ed Smith-Rowland wrote:
> Greetings,
>
> Jonathan had asked if I could make some simplifications to the organization
> of C++ versioning macros and namespaces in my standard literals patch.  I
> plum forgot to do it before I put in the patch.
>
> Also, I noticed I had picked up some garbage comments in the test cases.
>
> This patch cleans all that up.
>
> Built and tested on x86_64-linux.

This is OK for trunk, thanks.