Attempt to clean up if executor died while waiting on completion, or if
executor died while nomad agent is down.

Executor launch to return a cleanup state handle that can be used to
completely clean up executor resource and processes.

exitState is set in `wait()` goroutine but accessed in a different
`Wait()` goroutine, so accesses must be synchronized by a lock.

Freebsd vagrant fixes

* update versions of all products and add consul-template

* update client and server user_data scripts

* modify README.md and terraform.tfvars

* fix typo in consul-template system unit file

* update AMI id

fix possible panic in libcontainer shim init

* skeleton

* configure portworx

* destroy and redeploy mysql with data intact

* rename all directories and references from persistent storage to stateful workloads

* add considerations and remove references to StorageOS

* update wording and headings

* create portworx volume externally and modify jobfile to reflect that

* fix typo

* Update website/source/guides/stateful-workloads/portworx.html.md
Co-Authored-By: Omar-Khawaja <Omar-Khawaja@users.noreply.github.com>

* Update website/source/guides/stateful-workloads/portworx.html.md
Co-Authored-By: Omar-Khawaja <Omar-Khawaja@users.noreply.github.com>

Freebsd 11.1 went EOL 9/30/18:
https://lists.freebsd.org/pipermail/freebsd-announce/2018-September/001842.html

Was seeing a failure with shared object "libdl.so.1" not found which
is required for bash

Fix #5418

When using a docker logger that doesn't support log streaming through
API, currently docker logger runs a tight loop of Docker API calls
unexpectedly. This change ensures we stop fetching logs early.

Also, this adds some basic backoff strategy when Docker API logging
fails unexpectedly, to avoid accidentally DoSing the docker daemon.

Noticed that the protobuf files are out of sync with ones generated by 1.2.0 protoc go plugin.

The cause for these files seem to be related to release processes, e.g. [0.9.0-beta1 preperation](https://github.com/hashicorp/nomad/commit/ecec3d38de6ca72eea68d9737d7199cf67bbfe3e#diff-da4da188ee496377d456025c2eab4e87), and [0.9.0-beta3 preperation](https://github.com/hashicorp/nomad/commit/b849d84f2fc8b47c5f5b0e387bff4fa09c3bca6e).

This restores the changes to that of the pinned protoc version and fails build if protobuf files are out of sync.  Sample failing Travis job is that of the first commit change: https://travis-ci.org/hashicorp/nomad/jobs/506285085

Set shell to sh which is present by default on freebsd. Also set
networking to host dhcp due to limitations with NFS sharing:
https://github.com/hashicorp/vagrant/issues/9063

Fix bug with score metadata overridden during inplace upgrades

Fix regression with requiring docker auth email

This fixes a regression in 0.9 beta3 compared to 0.8.7 in validating
docker auth config

Fix task/logmon leak after crash

Some of the context uses in TR hooks are useless (Killed during Stop
never seems meaningful).

None of the hooks are interruptable for graceful shutdown which is
unfortunate and probably needs fixing.

Backward compat note about task config validation

artifact stanza documentation

Note rkt driver needs Nomad client run as root

Logs view - support widescreen format

The rkt driver requires that the Nomad agent to be running as the root user

drivers/shared/executor: fix strings.Replace call

nomad: compare current eval when setting WaitIndex

Made small adjustment to make it clear that 0.8.7 would require the legacy syntax and that the deprecation notice was more about the legacy syntax becoming unsupported at some point after v0.9.0

Add missing period to sentence.

To pick up https://github.com/hashicorp/hcl2/pull/90

Co-Authored-By: schmichael <michael.schurter@gmail.com>

Co-Authored-By: schmichael <michael.schurter@gmail.com>

Builds upon earlier commit that cleans up restored handles of terminal
allocs by also emitting terminated events and calling exited hooks when
appropriate.