Moved win32-specific code for net to detail.
Some compilation fixes.
Implemented yb::file on Linux.
Moved unix_system_error to utils.
Implemented console_stream for Unix.
Implemented linux_event.
Fixed linux_sync_runner.
Implemented refcount for Unix.
Implemented yb::group on Linux.
Implemented tcp_socket and tcp_listen.
Fixed Linux build.
Whitespace errors.