For non-slashed paths (e.g. Windows) `path` does the wrong thing.
Sadly this is not documented, but a cursory glance at the go sources
reveals that `filepath` uses `os.PathSeparator` everywhere while
`path` uses a literal `"/"`.
is no point to this.
All output (including TOC) is now written to a single output file.
This allows us to have different output file names to be specified.
Each for a different version generated code with its own build tags.
Consequently offering much greater flexibility in the way generated
code is to be used in a host application.
Fixes test outputs to match all these changes.
