REPRODUCIBLE_BUILD, part 2

REPRODUCIBLE_BUILD, part 2

Other half of the Debian reproducible-builds patch.  For Unix
Makefile.top, explicitly set locale to generic 'C' when running
'dlb' during install, so that wildcard expansion will yield a
predictable ordering regardless of collation order specified by
the local enviroenment.  Otherwise contents of the 'nhdat'
container might be different--when viewed as a single data file
itself--during subsequent rebuild even when no changes to source
or data have been made and each module inside remains the same.

This assumes that locale doesn't matter during generation of any
of the data files (whether destined for dlb or not).  I don't
think the utility programs attempt any sorting on the fly or
other locale-dependent output but wouldn't swear to that....