WIP: Fix build on windows

inc/lektor/internal/os.h

inc/lektor/internal/worker.h

inc/lektor/net.h

src/base/config.c

src/base/launch.c

src/base/logfile.c

src/base/os.c

src/database/cache.c

src/database/config.c

src/database/open.c

src/main/lkt.c

src/mkv/write.c

src/module/module_repo.c

src/net/listen.c