The wallet server now requires Perl 5.8 or later (instead of 5.006 in
previous versions) and is now built with Module::Build instead of
ExtUtils::MakeMaker.  This should be transparent to anyone not working
with the source code, since Perl 5.8 was released in 2002, but
Module::Build is now required to build the wallet server.  It is
included in some versions of Perl, or can be installed separately from
CPAN, distribution packages, or other sources.

Also reorganize the test suite to use subdirectories.

Change-Id: Id06120ba2bad1ebbfee3d8a48ca2f25869463165
Reviewed-on: https://gerrit.stanford.edu/1530


Reviewed-by: Russ Allbery <rra@stanford.edu>
Tested-by: Russ Allbery <rra@stanford.edu>