Add strings.h

[Ralf Corsepius]

On 12/07/2010 05:56 PM, Eric Blake wrote:
> On 12/07/2010 09:51 AM, Ralf Corsepius wrote:
>>
>> Next version of the patch enclosed below, this time with all
>> TBD's/ifdefs removed.
>
> Would you mind updating the patch so that if _POSIX_VERSION is defined
> and>= 200809L, then index() and friends are _not_ declared?
Why can't this patch be applied first and then modified by you afterwards?

As I already said in my initial submission, I have a long chain of 
patches depending on this patch waiting for submission.

Ralf