Filesystem helpers should be clearer in their semantics...

[JustinCappos]

I would have expected lindrustinit to also do operations similar to lindrustfinalize and gen_netdevs.sh. (If you have no idea what I mean, that is a big part of the problem!)

We absolutely need more documentation and possibly clearer behavior from the helper utility routines for Lind's rustposix interface. Right now the semantics are confusing and it is easy to get yourself in a situation where you are working with a messy state without being aware of it.