Gathering multiple system parameters in a single call

The "virtual file with 1 plain text value" model only really works very well for folks writing shell scripts, and breaks down otherwise. There are also repeated issues in sysfs where it's very difficult to decide what type of "thing" some directory represents because of how it lays out attributes.

It's clear that some nested key-value store is useful as a operating system API, and nested key-value store _is_ what the filesystem model is supposed to be. So it feels like improving the system call interface here to reduce overhead could be useful. Though perhaps some rethinking of the posix filesystem API also could make sense (transactions?)

Alternates might include leaning towards an RPC style interface, but that seems like we'd be reimplementing open/close/read/write on top of a stream like protocol. This _might_ make the efficiency better given syscall overhead though.