(module-ensure-local-variable!): Renamed from

(module-ensure-local-variable!): Renamed from
`module-ensure-variable!'.  Make sure that there really is a local
variable, not just a visible one.
(module-ensure-variable!): See above.
(module-export!): Behave like always when deprecated features are
enabled, but issue a warning when re-exporting a variable.  When
deprecated features are disabled, only export local variables,
creating them uninitialized when they don't yet exist.
(module-re-export!): New.  Use this for re-exporting imported
variables.
(re-export): New, to go with `module-re-export!'.

(named-module-use!, top-repl): Use resolve-interface
instead of resolve-module to get at the used module.