Workaround for gophercloud.ServerById crashing, fixes #1257

gophercloud.ServerById is broken in v0.1.0 - it will crash if you feed it a
non-existing server ID (see [rackspace/gophercloud #168](https://github.com/rackspace/gophercloud/issues/168))

Instead, list all servers and iterate over them. If the server id isn't found,
return "DELETED" as a state. Not perfect but it works until next version of
gophercloud is released.
Fix typo
Sort AMI names in Artifact.String - fixes random test failures

With go tip, the output from Artifact.String will sometimes be output in a
different order than the tests. Sort the AMI strings before outputting.
See https://travis-ci.org/mitchellh/packer/jobs/28748467 for an example of this
failure.
Merge pull request #1305 from lflux/sort-ami-strings

Sort AMI names in Artifact.String - fixes random test failures
Update CHANGELOG.md

builder/amazon-common: Sort AMI strings before outputting [GH-1305]
Merge pull request #1304 from lflux/fix-openstack-serverid-crash

Fix openstack ServerById crash
Update CHANGELOG.md

builder/openstack: Workaround for gophercloud.ServerById crashing [GH-1257]
Replace ListServers hack with update ServerById

[gophercloud#168](https://github.com/rackspace/gophercloud/issues/168) has been
patched to not panic on non-existing server id's. If an error is returned,
check if the error is a 404 first before bailing.
Merge pull request #1307 from lflux/better-serverbyid-fix

Replace ListServers hack with update ServerById
fix invalid esx5 path separator in windows

before, this code had joining path elements by filepath module. filepath module generate path string with backslash-joined in Windows. but ESX require path string with slash-joined. it means that this code generate illegal path string in windows. illegal path string raised "Error creating disk".

this patch fixes path separator from backslash to slash in windows. from this, creating disk would succeed without error.
Merge pull request #1316 from yuuzi41/fix-esx5-path-separator

fix invalid esx5 path separator in windows
Update CHANGELOG.md