Update job.html read most recent deployment sample

The sample request incorrectly used `https://nomad.rocks/v1/job/my-job/deployments` which listed all deployments for the specified job. The sample request has therefore been updated to use the correct endpoint which returns only the jobs most recent deployment.

Update raft to fix atomics alingment on 32bit

Allow template to set Vault grace

Related to #2963

Also pulls in some state file syncing improvements

autocomplete api

Use int32 for atomic ops to avoid alignment issues

Fix restoration of parameterized, periodic jobs

Add `dev/` for configs for use by Nomad developers

docs: fix tiny errors in monitoring spark app

docs: fix invalid links for hdfs examples

Fixes https://github.com/hashicorp/nomad/issues/2976

Small improvements to docs

Lost allocs replaced even if deployment failed

This PR fixes an incorrect placement of the update stanza in the task
and also links from the env stanza into an example of using the template
block to generate dynamic environment variables.

Document <task> network env vars

Looks like I accidently dropped them when combining env var listings in
PR #2709

add http tests for remaining contexts

Update revert.html.md.erb

wrong command

From https://golang.org/pkg/sync/atomic/#pkg-note-BUG :

On both ARM and x86-32, it is the caller's responsibility to arrange for
64-bit alignment of 64-bit words accessed atomically. The first word in
a global variable or in an allocated struct or slice can be relied upon
to be 64-bit aligned.

add tests for edge cases

extract magic number into variable

add test for when no prefixes are matched

add test for no context at HTTP api

set the index for a resources response