Rename windows-msvc platform to windows_msvc.
Change-Id: I4469ec2170f0b7237ae5d62271a98300ab4ca82f
Reviewed-on: http://review.couchbase.org/38869
Reviewed-by: Chris Hillery <ceej@couchbase.com>
Tested-by: Chris Hillery <ceej@couchbase.com>