Takes a map containing these keys:

`:exactly` The namespaces returned should be exactly these.
`:project?` If true, the namespaces should all belong to the project.
`:load-project-ns?` If true, the project namespaces will be loaded if they are not already.
`:has-tests?` If true, only return namespaces containing tests.
`:include-regexps` A list of regexps which the namespaces must match.
`:exclude-regexps` A list of regexps which the namespaces must not match.

Returns a list of namespaces as `find-ns` would return them on the host.

Takes a map containing these keys:
`:ns-query` A ns-query as `namespaces` takes, used to filter namespaces which contain vars.
`:private?` Include private vars in the results.
`:test?` Filter to vars which are also tests.
`:include-meta-key` A list of keywords searched for in the var's metadata, vars matching will be included.
`:exclude-meta-key` A list of keywords searched for in the var's metadata, vars matching will be excluded.
`:search` A regex to use for filtering vars, matches against `:search-property`.
`:search-property` Either :doc or :name, defaults to `:name`.
`:manipulate-vars` A callback run with the list of namespaces return by namespaces and the vars found within. Can be used to manipulate the list of vars before they are filtered.

Returns a list of vars, as the type that `var` would return on the host.