Source install: Customize service name and status

These changes affect source.sls only.

- Can now customize the name of the service.  'nginx' by default, or 'whatever-you-want' if you prefer.
- Can now optionally build + install without starting the service.
- Fixed a bug if the tarball_url was a Github tarball that extracted to a weird directory name.
- No longer implicitly delete *.default files, now if you want those gone, name them explicitly.