Don't try to build Windows SENS when not building for Windows.
Extract the relevant COM structs and typedefs from mingw-w64 headers
to allow to build the module with mingw.org toolchain and fix
build breakages with Microsoft compilers.
Check actually the return values and bail out if the registration
to receive system events failed.
Reformat the code to be consistent wrt tabs vs. space use.
Extract frequently used patterns into an inline function.
Make the MySensNetwork class inherit from ISensNetwork interface
instead of IDispatch (this assures, inter alia, that we use the
right function signatures for the callbacks).
Make the subscription to the network status notification receive
the event only if the ownerof the subscription is logged on to
the same computer as the publisher. This makes this module work
on Windows Vista and Windows 7 with normal user account.
The implementation is done using System Event Notification Service
by implementing ConnectionMade ConnectionMadeNoQOCInfo and
ConnectionLost methods of ISensNetwork interface.
Introduces C++ dependency for Windows port only
