response.body may be nil

we can get back things like http 204 with no response body and calling
chomp on that throws a bad stack track.  this sends nil back with
the response and the caller can determine how to handle the 204.
Remove the bootstrap templates that does chef install via gems.
Deprecate --distro and --template-file options in favor of --template.
Remove encrypted_data_bag_secret distribution via Chef::Config and enable distributing it via knife[:secret] and knife[:secret_file].
Fixes based on the PR comments.
Specs for bootstrap cleanup.
Fixes based on PR comments.
Update CHANGELOG and RELEASE_NOTES with bootstrap changes.
Merge pull request #1885 from opscode/sersut/bootstrap-12

Chef 12 bootstrap cleanup
Merge pull request #1896 from opscode/lcg/1869

response.body may be nil
Use homebrew for default package provider on OS X

Via Chef RFC 016[0], fixes issue #1709, adding the `homebrew_package`
resource with the `homebrew` provider, and setting it as the default
for Mac OS X platforms (`mac_os_x`, `mac_os_x_server`). This will
still require that homebrew is installed on the system somehow, but
doesn't require use of the cookbook if users choose to install via
some other method (pre-built images, for example).

[0]: https://github.com/opscode/chef-rfc/blob/master/rfc016-homebrew-osx-package-provider.md

Cleanup/fixes based on feedback

* Use accessor methods instead of instance variables for new_resource
  and current_resource in the provider.
* Use Chef::JSONCompat
* Move etc require to top
* Use let for homebrew_owner specs
* Set homebrew owner attribute and remove ENV stubs
* Add repeated stubs in LCR to a before block
* Wrap action method tests in a context so provider.current_resource
  does the right thing
* Add timeout for #get_response_from_command (bonus, per
  #opscode-cookbooks/homebrew issue 49)

Better exception for homebrew owner mixin

Create an exception class for when the owner isn't found, subclassed
from Package. Update the exception output text.