* client.cc: Revert changes to handle 32 bit processes on 64 bit
	systems.
	* sysv_msg.cc: Ditto.
	* sysv_sem.cc: Ditto.
	* sysv_shm.cc: Ditto.
	* cygserver.h (struct header_t): Revert msglen to simple member.
	Drop accessor methods.
	* cygserver_ipc.h (struct proc): Drop enforced 4 byte struct packing.
	Remove members for 64<->32 bit IPC.  Revert to original member order.
	(ipc_set_proc_info): Remove 64<->32 handling.
	(conv_timespec32_to_timespec): Delete.
	(conv_timespec_to_timespec32): Delete.
	* pinfo.h (struct win_heap_info): Remove.
	* shm.cc (fixup_shms_after_fork): Revert parent initialization.
	* winlean.h: Remove _TYPE64_CLR and _TYPE64_SET macros.  Remove
	usage throughout code.
	* include/cygwin/ipc.h: Drop 64<->32 bit helper structures.
	* include/cygwin/msg.h: Ditto.  Drop enforced 4 byte struct packing.
	* include/cygwin/sem.h: Ditto.
	* include/cygwin/shm.h: Ditto.
	* include/cygwin/sysproto.h: Drop enforced 4 byte struct packing.
	* exceptions.cc (rtl_unwind): Convert to macro doing nothing on x86_64.
	(exception::handle): Drop creating frame variable on x86_64.
	* wincap.cc (wincap_2000sp4): Set has_rtl_capture_context to false.
	* autoload.cc (AttachConsole): Remove.
	(GetModuleHandleExW): Remove.
	(GetSystemWow64DirectoryW): Remove.
	(GetVolumePathNamesForVolumeNameW): Remove.
	* exceptions.cc (cygwin_stackdump): Always call RtlCaptureContext.
	(exception::handle): Drop accidentally left in debugging statement.
	Always call RtlCaptureContext.
	(sigpacket::process): Always call RtlCaptureContext for current thread.
	* fhandler_disk_file.cc (fstatvfs): Drop code using
	FileFsSizeInformation.
	(struct __DIR_cache): Remove comment.
	(fhandler_disk_file::rewinddir): Drop W2K-only code.
	* fhandler_floppy.cc (fhandler_dev_floppy::get_drive_info): Don't
	check for old OS.  Extend a comment.
	* fhandler_mem.cc (fhandler_dev_mem::open): Drop NT4 and W2K from
	debug output.
	* fhandler_proc.cc (format_proc_partitions): Drop Pre-XP considerations.
	* fhandler_procnet.cc (fhandler_procnet::exists): Ditto.
	(fhandler_procnet::readdir): Ditto.
	(format_procnet_ifinet6): Ditto.
	* fhandler_socket.cc (fhandler_socket::recvmsg): Ditto.
	* fhandler_tape.cc (mtinfo_drive::get_status): Ditto.
	* init.cc (dll_entry): Drop W2K-only code.
	* net.cc (get_ifs): Rename from get_xp_ifs.
	(get_2k_ifs): Remove.
	(getifaddrs): Always call get_ifs.
	(get_ifconf): Ditto.
	(if_nametoindex): Drop Pre-XP considerations.
	(load_ipv6_funcs): Ditto.  Fix preceeding comment.
	* sec_auth.cc (lsaauth): Drop code handling fake_login_sid.
	* sec_helper.cc (fake_logon_sid): Remove.
	(set_cygwin_privileges): Fix uncommented statement to drop pre-XP
	considerations.
	* security.h (fake_logon_sid): Drop declaration.
	* shared.cc (shared_info::init_obcaseinsensitive): Drop W2K-only code.
	* wincap.cc: Throughout, remove setting all deprecated wincapc members.
	(wincap_minimal): Set to wincap_xpsp2.
	(wincap_2000): Remove.
	(wincap_2000sp4): Remove.
	(wincap_xp): Remove.
	(wincap_xpsp1): Remove.
	(wincapc::init): Drop OS 5.0 and pre-SP2 XP.
	* wincap.h (struct wincaps): Remove the following members:
	has_create_global_privilege, has_ioctl_storage_get_media_types_ex,
	has_disk_ex_ioctls, has_buggy_restart_scan, needs_logon_sid_in_sid_list,
	has_gaa_prefixes, has_recvmsg, has_stack_size_param_is_a_reservation,
	kernel_is_always_casesensitive, has_rtl_capture_context.
Pull in changes from HEAD