<!--- Verify first that your feature was not already discussed on GitHub -->
<!--- Complete *all* sections as described, this form is processed automatically -->

##### SUMMARY
The `win_dns_client` module always shows "changed" when setting the adapter to use DHCP because the PowerShell cmdlets and WMI classes don't have a reliable way to determine that DHCP assigned nameservers are already in use.

A comment in the module suggests checking the registry.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
win_dns_client

##### ADDITIONAL INFORMATION
<!--- Describe how the feature would be used, why it is needed and what it would solve -->
As is, it's not possible to know whether a change was actually made (or would be made in check mode).
<!--- Paste example playbooks or commands between quotes below -->

<!--- HINT: You can also paste gist.github.com links for larger files -->

detect the difference between a DHCP-sourced server value and one that is statically set.
author:
- Matt Davis (@nitzmahone)
'''
EXAMPLES = r'''
- name: Set a single address on the adapter named Ethernet
  win_dns_client:
    adapter_names: Ethernet
    dns_servers: 192.168.34.5
- name: Set multiple lookup addresses on all visible adapters (usually physical adapters that are in the Up state), with debug logging to a file
  win_dns_client:
    adapter_names: '*'
    dns_servers:
    - 192.168.34.5
    - 192.168.34.6
    log_path: C:\dns_log.txt
- name: Set IPv6 DNS servers on the adapter named Ethernet
  win_dns_client:
    adapter_names: Ethernet
    dns_servers:
    - '2001:db8::2'
    - '2001:db8::3'
- name: Configure all adapters whose names begin with Ethernet to use DHCP-assigned DNS values
  win_dns_client:
    adapter_names: 'Ethernet*'
    dns_servers: []
'''
RETURN = r'''
'''