iis : iis_site autostart options largely undocumented

OS Name/Version: Windows

When I set serviceautostart: true without setting either serviceautostartprovidername or serviceautostartprovidertype within an iis_site resource, I expected that the website would automatically start on the next reboot, using the default mechanism.

Desired Behavior:

As it turns out, if serviceautostart is true, then serviceautostartprovidername and serviceautostartprovidertype must both be non-blank, although it is still unclear to me what constitutes a valid value for each setting. To be fair, the official Microsoft documentation, part of which is repeated by the iis module, is equally inadequate.

At a minimum, setting serviceautostart to true without supplying non-blank values for both serviceautostartprovidername and serviceautostartprovidertype should have resulted in a compile-time error.

Actual Behavior:

The setting had no effect, and subsequent puppet runs re-applied the setting as a corrective change.