builder/amazon-chroot: Only unmount if path is actually mounted

builder/qemu: Force qemu to use a VNC port by setting vnc_min_port == vnc_max_port

Similar to Issue #1288, this prevents a crash when we set the VNC
minimum port equivalent to the VNC maximum port

communicator/ssh: support for bastion SSH

Windows provisioners: powershell, windows-shell, windows-restart

provisioner/puppet-masterless: only base if manifest is a file [GH-1933]

Add quickfix to restart provisioner as existing one was not working.

For more information read https://github.com/mitchellh/packer/pull/2243

packer: HookProvision errors if no communicator

website: adds missing comma

The `parallels_tools_flavor` key-value pair is missing a trailing comma, thereby making it invalid JSON.

Merge branch 'puppet_working_dir' of https://github.com/ColinHebert/packer into ColinHebert-puppet_working_dir

provisioner/shell: remove file after exec [GH-1536]