c: Avoid including winsock2.h in ip_connection.h

Either winsock2.h must be included before windows.h or
WIN32_LEAN_AND_MEAN must be defined to suppress the inclusion of
winsock.h by windows.h, beucase winsock.h conflicts with winsock2.h.
This means that ip_connection.h could not be included after windows.h
if WIN32_LEAN_AND_MEAN was not defined.

Avoid this situation by removing the include of winsock2.h from
ip_connection.h.
Set response-expected to true by default for all callback config functions

In the common case callback configuration functions aren't called that
often, therefore this doesn't result in a general performance penalty.
Changing the response-expected default for them to true is better for
callback driven programs that would otherwise not notice when a device
doesn't response properly.
c: Change signature of response-expected related function to be generatable
gps: Specify the reference system for the course
gps: Fix typos