Fixed error with empty shell provisioner

`read` returns nil on empty files, so the call to `valid_encoding` fails.
core: can't add boxes from network shares [GH-3279]
Merge pull request #3423 from bmorg/fix_empty_shell_provisioner_error

provisioner/shell: error with empty shell provisioners
Update CHANGELOG
website/docs: clarify docker
kernel/v2: clear ID field so its not passed to provisioner [GH-3424]
guests/coreos: docker_daemon_running cap [GH-3425]
Remove this, supposed to be in vagrant-next
provisioners/ansible: refer to inventory directory

By referring the directory that contains the generated inventory file,
users can easily provide more settings with additional files stored in
the same directory.
print version when removing a specific box

Example:

$ vagrant box remove --box-version 0.2.9 berendt/ubuntu-14.04-amd64
Removing box 'berendt/ubuntu-14.04-amd64' with provider 'virtualbox' in version '0.2.9'...
fixed spelling
sort versions and print them as listing

before this patch:

```
$ vagrant box remove --box-version 0.2.9 berendt/ubuntu-14.04-amd64
You requested to remove the box 'berendt/ubuntu-14.04-amd64' version '0.2.9' with
provider 'virtualbox', but that specific version of the box is
not install. Please double-check and try again. The available versions
for this box are:

0.2.11, 0.2.10
```

after this patch:

```
You requested to remove the box 'berendt/ubuntu-14.04-amd64' version '0.2.9' with
provider 'virtualbox', but that specific version of the box is
not install. Please double-check and try again. The available versions
for this box are:

 * 0.2.10
 * 0.2.11
```
Merge pull request #3440 from berendt/fixing_typo_001

fixed spelling
Merge pull request #3438 from berendt/show_version_when_removing_a_specific_box

print version when removing a specific box
Nitpick on messaging
Merge pull request #3441 from berendt/sort_versions_and_print_listing

commands/box/remove: sort versions and print them as listing
core: No need to map! here
add translation message for docker building images
Merge pull request #3445 from Mulkave/fix/master/missing-translation-docker-building-images

add missing translation message for docker_building_images
style