(CFACT-117) Add Windows networking facts

Adds Windows networking facts, implemented according to facter's behavior.
That includes allowing different primary interfaces for IPv4 and IPv6, but
using the IPv4 primary interface for the primary MAC address.

Major changes were:
- Refactoring the wmi API to return a vector of objects when multiple
  objects are returned, rather than returning those results split into
  ranges of values.
- Returning array values from wmi.
- Added an optional primary IPv6 interface property.