cmd/flux-kvs: Remove legacy --json options and json output

[chu11]

Per #2796, remove legacy --json options in flux kvs and remove json output from flux kvs dir.

The meat of this PR is the changing on the tests, which is in 1 huge commit. Outside of just removing the --json calls, there had to be tweaks to the tests and the removal of a few that were --json specific.

[chu11]

Doh, missed that flux-sched has a flux kvs -j call in flux-tree (only searched --json). Will have to push a PR there too.

[dongahn]

@SteVwonder tested this and found the following works:

< flux --parent kvs put -j "tree-perf=${blurb}" || warn "KVS error"
> flux --parent kvs put --raw "tree-perf=-" <<< "${blurb}" || warn "KVS error"

[chu11]

Hmmm, asan builder hung (which I think happens once in awhile), but had one builder just fail with

FAIL: t2007-caliper.t 1 - --caliper-profile works

FAIL: t2007-caliper.t 2 - caliper output file exists

           t2007-caliper.t:  FAIL: N=3   PASS=1   FAIL=2 SKIP=0 XPASS=0 XFAIL=0

ERROR: t2007-caliper.t - exited with status 1

Not really sure about what could have caused this.

also, found typo in a commit message and I forgot 1 --json call in the tests. So rebased & re-pushed.

[chu11]

Hmmm asan builder got

        t2200-job-ingest.t:  SKIP: N=0   PASS=0   FAIL=0 SKIP=0 XPASS=0 XFAIL=0

ERROR: t2200-job-ingest.t - missing test plan

ERROR: t2200-job-ingest.t - exited with status 1

caused by

ERROR: t2200-job-ingest
=======================

Alarm clock
error: failed to find lua posix module in path
ERROR: t2200-job-ingest.t - missing test plan
ERROR: t2200-job-ingest.t - exited with status 1

Which likely came from

#  Test requirements for testsuite
if ! run_timeout 1.0 lua -e 'require "posix"'; then
    error "failed to find lua posix module in path"
fi

I'm guessing 1.0 seconds timed out ...

Added a patch to increase that timeout, re-pushed PR.

[garlick]

Nice cleanup! This looks good to me.