Delete Chef client and node on cleanup

This fixes #1253 by shelling out to `knife` on cleanup, as per
@mitchellh's suggestion in #1255
Show node name in logging
Suppress knife output
Allow non privileged user vagrant to run a shell provision
Use current user's uid for NFS exports
added ssh.proxy_command to handle waiting for aws ssh connection when ssh proxy in place.  use config.ssh.proxy_command = "ssh -q <user>@<proxy_host> nc %h %p"
pushing salt provisioner
Add OpenSUSE network settings
more concise message for BoxNotFound error

Now we have different providers, but the error message didn't tell
anything about it. Suppose I want to remove one of my boxes:

    vagrant box remove opscode-ubuntu-12.04 vritualbox

There is a typo in provider name. The error message is:

    Box 'opscode-ubuntu-12.04' could not be found.

Therefore I need to double check the box name, and only than I will see
the typo.

This commit make the error message looks like this:

    Box 'opscode-ubuntu-12.04' with 'vritualbox' provider could not be
found.
Add support for "ansible.tags" attribute
Add a Joker to pass raw options to ansible-playbook call
Support different verbosity levels with 'ansible.verbose'
fix uninitialized constant error for gentoo plugin
Fix typo error (single dash: -vv not --vv)
respect :nic_type option for private network. Fixes #1704
Emit 'vagrant-mounted' on Ubuntu in mount_virtualbox_shared_folder capability

Also includes the same, but commented out, for mount_nfs capability
Fix typo.
Add support for "ansible.start_at_task" attribute
protected not private
Import the TemplateRenderer (like the other guests do).