Fix alloc health with checks using interpolation

Template emits events explaining why it is blocked

Migrate nomad status to nomad job status

AMI ID is potentially non-unique

Code highlighting

This PR does the following:
* Adds a mechanism to emit events in the TaskRunner
* Vendors a new version of Consul-Template that allows extraction of
missing dependencies
* Adds logic to our consul_template.go to determine missing events and
emit them in a batched fashion.
* Refactors the consul_template code to split the run method and take in
a config struct rather than many parameters.

Fixes https://github.com/hashicorp/nomad/issues/2578

Changed the keys map to reflect that.

Terraform: enable Consul UI and bind Nomad to all interfaces

Redact Vault.Token from AgentSelf response.

Re-added Allocations documentation 

Code cleanup

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.

If Config.Vault.Token is defined, /v1/agent/self will return the string
`<redacted>`. If the token is not set, This endpoint will continue to
return the empty string.

Update raft to fix atomics alingment on 32bit

Allow template to set Vault grace

Fixes an issue in which the allocation health watcher was checking for
allocations health based on un-interpolated services and checks. Change
the interface for retrieving check information from Consul to retrieving
all registered services and checks by allocation. In the future this
will allow us to output nicer messages.

Fixes https://github.com/hashicorp/nomad/issues/2969

Related to #2963

Also pulls in some state file syncing improvements

In a content reorganization, the allocations endpoint documentation was removed.  This just brings it back in and updates the output to match v0.6.0 output

autocomplete api

Use int32 for atomic ops to avoid alignment issues