Originally introduced by me based on high hopes and cross-platform
usage.  I was wrong.

A PATH without /usr/local/(s)bin, as advertised by the standard rc(8)
system or service(8) will prevent env(1) from working properly.  We've
had similar fun with configd before.  Maybe we need to take this to FreeBSD.
For now we work around it like every body else, presumably.  :)

Discussed with: Shawn Webb

pkgng isn't there yet.

This was leaking spurious json output sometimes, confusing
the firmware pages and its users.

Discussed with: ad@

Shell access is sufficient, I see absolutely no value in this.

(configd) flush script output to tempfile to avoid the use of subprocess.check_output which can be slow on some platforms.