Fixed deprecation warnings for use of Chef::ShellOut

When using Chef::ShellOut with chef-client 11.x, the following warnings come up during a run:

```
[2013-02-14T20:28:19+00:00] WARN: Chef::ShellOut is deprecated, please use Mixlib::ShellOut
[2013-02-14T20:28:19+00:00] WARN: Called from:
  /tmp/vagrant-chef-1/chef-solo-1/cookbooks/java/providers/ark.rb:68:in `new'
  /tmp/vagrant-chef-1/chef-solo-1/cookbooks/java/providers/ark.rb:68:in `block in download_direct_from_oracle'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.0/lib/chef/mixin/why_run.rb:52:in `call'
  /opt/chef/embedded/lib/ruby/gems/1.9.1/gems/chef-11.4.0/lib/chef/mixin/why_run.rb:52:in `add_action'
```
Changed all calls to Chef::ShellOut to Mixlib::ShellOut