[Box Backup] Problems moving the store location

[Stefan Norlin]

Another question would be if the HAVE_VALID_DIRENT_D_TYPE
and HAVE_STRUCT_DIRENT_D_TYPE macros are really necessary
or whether their use could be eliminated?

I see Martin added the check to infrastructure/m4 and the
HAVE_VALID_DIRENT_D_TYPE seems to be used in 3 different
places but I cannot tell if it is possible to live without it or not...

Anyway a d_type == DT_UNKNOWN assert or check somewhere
could be a good way of "visualizing" the problem.

Stefan