Registry layer relies on standard plugin

[ikelos]

Describe the bug
A core part of the framework (registry layer) relies on pslist to figure out the process that the registry lives in. This is an awkward introduces a lot of cross-dependency that shouldn't exist. We should try to find a way to achieve the same goal without pulling in so much extra gubbins just to find the process list. I'd almost be happy duplicating code, or storing it in a separate common module (perhaps the generic process work from #1000 could help)?

See #1307 for more details.