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

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.

Reformat docs using htmlbeautifier and pandoc

Updated docs on how AWS credentials are resolved

Document behavior of AWS {access,secret}_key in relation to credentia…

Update setup documentation to cover issue #1117

Fixes #2478