builder/amazon/ebs: Add config for target AZ.

builder/virtualbox: arguments Prefix (--) was missing for (sata)portconfig

Conflicts:
	CHANGELOG.md

Fixes missing entropy in the uuid package.

math/crypto is seeded with 1 and thus will create predictable UUIDs. Because
amazon-instance and amazon-ebs in the same second when building both targets
the timestamp in front doesn't help either. See #552

[GH-536]

Fixes [GH-536]

provisioner/ansible-local: Add support for provisioning with Ansible

post-processors/vagrant: add compression_level option

provisioner/salt-masterless: use communicator.UploadDir

provisioner/salt-masterless: move states to /srv/salt, not /srv/salt/states

[GH-539]

post-processor/vagrant: fix bug in ova support caused by wrong file path

builder/amazon/chroot: use --remove-destination for cp 

contributing: clarify how to submit debug output with a new issue

Delete files at destination before copy. This should help with the dangling
symbolic link issue we've been seeing with ubuntu.

fixes GH-500

fix typo in docs for saltmasterless provisioner. 

website/docs: note shutdown to run as root, why