agent: Adding remote exec configuration
agent: Refactor msgpack serialization into util
command: Adding method to get client with datacenter
command/exec: First pass at exec command
agent: First pass at remote exec support
command/exec: Fixing use of shutdown ch
agent: testing remote exec writer
agent: Refactor remote exec write code
agent: Testing remote exec
command/exec: High level tests
command/exec: Testing exec
command/exec: Fixing verbose flag
agent: Handle cancel for idle wait
command/exec: Tuning constants
command/exec: Improving output
website: Updating docs
Merge pull request #312 from hashicorp/f-rexec

Adding support for 'exec' command