This generally seems like a better name, especially if we somehow also
need a better name for "read the entire buffer, but not the entire file"
somewhere down the line.
This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.
One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.
This happens in two ways:
1. LibCore now has two new methods for creating Jails and attaching
processes to a Jail.
2. We introduce 3 new utilities - lsjails, jail-create and jails-attach,
which list jails, create jails and attach processes to a Jail,
respectively.
