output: change '-' to mean stdout rather than stderr.
output: change '-' to mean stdout rather than stderr.

This is more consistent with '-' generally meaning stdout in
other programs.

In addition, "/dev/stderr" is now recognized as meaning stderr
(including on Windows).

Fixes #201.

a1lu/Criterion,am11/Criterion,a1lu/Criterion,offa/Criterion,offa/Criterion,offa/Criterion,Snaipe/Criterion,a1lu/Criterion,Snaipe/Criterion,am11/Criterion,Snaipe/Criterion,offa/Criterion,am11/Criterion,a1lu/Criterion,a1lu/Criterion,am11/Criterion,Snaipe/Criterion,offa/Criterion,am11/Criterion,Snaipe/Criterion