* fhandler_dsp.cc (fhandler_dsp::ioctl): Return 0 for successful

* fhandler_dsp.cc (fhandler_dsp::ioctl): Return 0 for successful
SNDCTL_DSP_GETBLKSIZE operation.  Remove obsolete 'name' arg from fhandler_*
constructors throughout.
* winsup.h (winsock_active): New macro.
(winsock2_active): Ditto.
* autoload.cc (wsock_init): Use new macros to decide if winsock or winsock2 is
loaded.
(nonexist_wsock32): Dummy function to force winsock load.
(nonexist_ws2_32): Dummy function to force winsock2 load.
* fhandler.h (fhandler_socket::fstat): Declare new method.  Currently unused.
* fhandler_socket.cc (fhandler_socket::fixup_before_fork_exec): Check that
winsock2 is active before trying WSADuplicateSocketA.
(fhandler_socket::fixup_after_fork): Add extra check for winsock2_active.
Otherwise use iffy procedures for Windows 95.
(fhandler_socket::fixup_after_exec): Add debugging.
(fhandler_socket::dup): Add debugging.
(fhandler_socket::fstat): New method.
(fhandler_socket::set_close_on_exec): Attempt to perform iffy stuff on Windows
95.
* errno.cc (_sys_nerr): Work around compiler strangeness.
* pinfo.cc (winpids::add): Add extra element at end of allocated array for
setting to NULL.
(winpids::enumNT): Ditto.
(winpids::init): Don't modify pidlist if it hasn't been allocated
(possibly due to malloc problem).