cgroup's are applicable to Windows and will require a more specific abstraction.  Stub out the difference.  The *NIX exec drivers will likely be broken out over time (e.g. *BSD and Solaris).

Exclude broken build targets from gox

Favor the `unix` package on *NIX platforms vs the now frozen `syscall` package.

`!windows` was being used as the synonym for `darwin dragonfly freebsd linux netbsd openbsd solaris`.  While I don't imagine `android` will be a prime target for Nomad in the near term, favor explicit build targets.

List of build targets generated by Go 1.7's dist command: `go tool dist list | sort | cut -d '/' -f 1 | sort | uniq`

Use the `_unix` file suffix to denote *NIX-like semantics in order to parallel the designation given by the package `golang.org/x/sys/unix`.

Added logs to indicate when checks timeout

Update Vagrantfile to support multiple nodes. Bump Go to 1.6.2.

dadgar: "LGTM"

`vagrant up` just works and only one VM is spun-up by default, however
there are up to 5x VMs available for cluster testing. `nomad-server%02d`
and `nomad-client%02d`.

Include the current version along side the available version.

date, include the current version along with the available version
according to checkpoint.

Inspired by: log output in hashicorp/consul#993

Use govendor

```
govendor remove +unused
git add vendor/
```

No functional change.

```
govendor update github.com/ugorji/go/codec
govendor update github.com/ugorji/go/codec/codecgen
```

Ensuring check names are unique

Ensuring service names are unique

Added docs for json representation of service discovery objects

Track enhanced links

Fix typo in force-leave docs

Task is not eligible for update if User, Meta, or Resources change

Docker labels configuration should be of type "array" in schema

Do not allow referrer to modify the sender

http://mathiasbynens.github.io/rel-noopener/