import `slugs` in function `interfaces.slugs.synthesize`
import `slugs` in function `interfaces.slugs.synthesize`

to avoid cyclic imports when using some other function from `interfaces.slugs` from within a module also named `slugs` (but different from the package that is included with slugs), when this other module is imported in a script.

See also comment in 26ff039585166d2c2b2027fc8e61f863ad94fd1f for the use case of generating "slugsin" from code different than the compiler included with `slugs`.
necozay/tulip-control,necozay/tulip-control,necozay/tulip-control,tulip-control/tulip-control,tulip-control/tulip-control,necozay/tulip-control,tulip-control/tulip-control,tulip-control/tulip-control,necozay/tulip-control