Add options to specify salt remote dirs

Ensure that `/etc/salt` exists

Merge branch 'openstack_metadata' of https://github.com/trumant/packer into trumant-openstack_metadata

Fix handling IPv6 when ssh_interface set (openstack builder)

Updated how vmx entries are handled

Fix funny characters.

Do not require exclusive VNC access while buildling

An additional client can be connected during build time for inspection.
We can manually connect and set our VNC clients to ignore all input or
we can connect with vnc2flv to record the build session for later
verification.

Fix semantic errors in messages

Revise documentation for minion config

amazon/common: store instance ID earlier for cleanup

Updated AWS SDK calls to match the 0.7.0 release of the AWS SDK

Fix powershell elevated not setting variables properly.

builder/googlecompute: Document use_internal_ip

Fix bug on WinRM connector

Make sure that directory `/etc/salt` exists before copying salt
minion file.

* It is possible to set remote salt tree through `remote_state_tree` argument.
* It is possible to set remote pillar root through `remote_pillar_roots` argument.
* Directories `remote_state_tree` and `remote_pillar_roots` are emptied before use.

* Update link to salt minion config.
* Clarify that minion config is a file.

openstack: store updated accessIPv4 from RackConnect

openstack builder: support using existing keypair

openstack builder: log which IP address SSH will use

Fix example code for digital ocean builder

Remove command after size

Add s.SSHPort variable as the port WinRM uses to connect. This is needed on any builder where the port used to connect is not the guest winrm port but a nated port on the host.
Similar behavior is used by the SSH communicator.