Check_MK Werk 5688: Windows agent: numerous fixes to only_from

ID: 5688 Title: Windows agent: numerous fixes to only_from Component: Checks & agents Level: 1 Class: Bug fix Version: 1.5.0i3 The setting only_from was handled improperly in many ways: * The IPv4 loopback address 127.0.0.1 did not always work in only_from, depending on what kind of client was used on localhost. Now if the IPv4 loopback address is given in only_from, the corresponding IPv6 loopback ::1 is added there to ensure the correct functionality with different clients on localhost. * IPv6 addresses converted from only_from IPv4 addresses were not output in section Check_MK. This was a regression from 1.2.8 introduced in the huge refactoring c5ee818358e695b01c2f2dbc05ad0713723a37f8. * IPv6 addresses were output incorrectly in section Check_MK: * the last colon-separated group was always missing. * the groups were output as decimal instead of hexadecimal digits. * the groups were output in network byte order instead of host byte order, leading to incorrect output.