use NtSetInformationFile if os.Rename fails

[karman-docker]

This PR adds atomicwriterRenameAt which uses NtSetInformationFile to rename a file on Windows.

[kolyshkin]

This obviously needs some windows-specific tests.

[kolyshkin]

nit: you've introduced atomicwriterRenameAt in the first commit, and then rename it to atomicwriterRename in the second commit. Why not use the right name from the start?

nit: stuttering at the name (atomicwriter.atomicwriterRename).

[karman-docker]

nit: you've introduced atomicwriterRenameAt in the first commit, and then rename it to atomicwriterRename in the second commit. Why not use the right name from the start?

nit: stuttering at the name (atomicwriter.atomicwriterRename).

sorry I thought in your initial review comment, you suggested to remove 'At' ?

[kolyshkin]

nit: you've introduced atomicwriterRenameAt in the first commit, and then rename it to atomicwriterRename in the second commit. Why not use the right name from the start?
nit: stuttering at the name (atomicwriter.atomicwriterRename).

sorry I thought in your initial review comment, you suggested to remove 'At' ?

Yes, but here I'm not saying At should be back, I am saying the right name should be introduced from the start, i.e. in the first commit.