basic Nm template engine

This engine renders the given path, in the source path, using Nm.
Sanford then takes the rendered template data and serializes it to
BSON as needed.

This engine memoizes the Nm source and binds to an overridable
scope name method, 'view'.

This should be all that is needed to have a working sanford Nm
template engine.
update to support locals

Sanford's engine api now takes locals.  This updates the engine to
honor locals that are passed to it.

This also updates the handling of the passed servicd handler.  This
is no longer referred to generically as "scope" but instead specifically
as "service handler".  This option to override the handler local
name has also been updated to better intend its purpose.

This just makes the engine compatible with the latest Sanford engine
API.