plugins probed even if not using entrypoints

[toppk]

I'm using aiohttp-s3-client and I'm getting pkg_resource not found.

I could give in and install setuptools, or set the AIOMISC_NO_PLUGINS variables, but I consider the automatic probing for plugins to be unnecessary. It seems that PLUGINS are specifically tied to aiomisc.entrypoint() API, which aiohttp-s3-client doesn't use.

maybe aiomisc.entrypoint.entrypoint can run setup_plugins() before returning Entrypoint, that setup_plugins doesn't need to be called on import.