TAP::Harness and the w flag

There are two changes under scrutiny: the first removed "turn on -w by default with no easy way to turn it off", and the second reverted it:

https://github.com/Perl-Toolchain-Gang/Test-Harness/commit/18794a85

https://github.com/Perl-Toolchain-Gang/Test-Harness/commit/99159fc2

Discussion summary so far:

schwern  : We need to discuss this, and please see https://rt.cpan.org/Ticket/Display.html?id=58229
ether    : We should keep the original change.
mst      : We should keep the original change.
miyagawa : We should keep the original change.
leont    : We should keep the original change.
ewilhelm : We should keep the original change, but update EUMM to restore -w
ribasushi: I don't see a reason to change the old behavior.
rjbs:    : in favour of the original change

Pull request to document the two changes, with a bit of discussion: https://github.com/Perl-Toolchain-Gang/Test-Harness/pull/16

perl-qa thread: http://www.nntp.perl.org/group/perl.qa/2013/07/msg13468.html