ruby-shadow supports darwin+freebsd now

- comment in https://tickets.opscode.com/browse/CHEF-4402
CHEF-5030: improve debian ifconfig provider code

- dynamically create directory resource to create /etc/network/interfaces.d
- better idempotency and accuracy in what we report to the user
- dependency injection in tests that uses real tempfiles instead of mocking File class, etc
Merge pull request #1289 from opscode/lcg/CHEF-5030

CHEF-5030:  improve debian ifconfig provider code
Update md files for three merged issues

oops, i forgot we're doing this now...
Merge pull request #1290 from opscode/lcg/md-files

Update md files for three merged issues
Merge pull request #1126 from opscode/lcg/ruby-shadow-2.3.1

CHEF-4773: ruby-shadow supports darwin+freebsd now
release notes for CHEF-4773
Add enable/disable to MacOSX service provider

v11 version of #1267
Merge pull request #1292 from jaymzh/macosxfixes-11

Add enable/disable to MacOSX service provider
CHEF-5086: Add CHANGELOG and RELEASE_NOTES for reboot_pending?