Make depslog v1->v3 message less scary.

See the comment 5 lines up for details.
Merge pull request #653 from nico/msg

Make depslog v1->v3 message less scary.
Fix for build test for BuildWithDepsLogTest.RestatMissingDepfileDepslog
Merge pull request #654 from rgeary1/buildTestFix

Fix for build test for BuildWithDepsLogTest.RestatMissingDepfileDepslog
Simplify.
Merge pull request #655 from nico/simp

Simplify.
add -d keeprsp to preserve @rsp files on success on windows
Merge pull request #657 from sgraham/keeprsp2

add -d keeprsp to preserve @rsp files on success on windows
mark this 1.4.0.git, update RELEASING