Fix MinGW build

Fix some issues with CAF on MinGW:
- Correctly initialize networking on Windows using WSAStartup()
- Rename `interface` member function to `message_types` because `interface` is
  a define on Windows (srsly Microsoft?)
- Cast to correct pointer type when using `send` or `recv`
- Fix some warnings caused by using `int` instead of `native_socket_t`

  The issues have been reported by GitHub user xmt.
Rename or remove any identifier called `interface`

This fixes an issue on Windows where `interface` is an alias for `struct`.
Merge branch 'topic/rename_interface'
Workaround for platforms w/o POLLPRI
Merge branch 'topic/POLLPRI_workaround'
Do not use POLLPRI on Windows
Merge branch 'topic/no_POLLPRI_on_Windows'
Make event_based_actor::forward_to public
Change version to 0.10.2