s3-vfs: split @GMT token filter code into a common .c

[Christian Ambach]

On 10/30/2012 02:58 PM, Volker Lendecke wrote:

>> Do you know of anyone using the undocumented snapdirseverywhere option?
>
> Yes, GPFS based systems can require it.

Yup, when using independent filesets.. I'll push a documentation patch.

Cheers,
Christian