Use atree for the Windows SDK. Strip binaries.

Use atree for the Windows SDK. Strip binaries.

This moves the copy/strip/rm logic for the Windows SDK
fro mthe patch_windows_sdk.sh to a regular tools.windows.atree.

The bash script is still here to invoke atree and do whatever
cleanup we might want to do later.

This should make it easier to maintain the Windows SDK
by providing a structure similar to tools.atree.

This change requires build.git Change-Id: I22aae7a8 to
have rm/strip support in atree.

Change-Id: Ie6c30979454fb71fc1cb26ab3f6c38acd47bae57