Add max_align_t.

ok millert@

Move the 10 (!) defintions of NULL to their own mini header file and
update the NULL definition for C++11. OK deraadt@ guenther@ kettenis@

As pointed out by Richard Guenther our definition
of NULL was incorrect for c++ compilers that aren't
gcc (or pretend to be gcc like clang).

ok miod@

Define NULL as a void * instead of a long integer, as required by Single Unix.
Kernel and bootblocks still use the old 0L value until all the NULL abuses
in the code are fixed.

Use __builtin_offsetof for offsetof definition on gcc >= 4
This is required as gcc grows ever more pedantic with old age
and cavorts with standards bodies that like to create paradoxes.

ok kettenis@ miod@ millert@ espie@

Adapt things to use __type_t instead of _BSD_TYPE_T_
Add new sys/_types.h header
Include machine/_types.h or sys/_types.h where applicable

major abi changes:

* introduce the mbstate_t typedef.
impacts gnu libiconv, which has already been taken care of.

* Prepare for mb stuff to really exist, replace macro MB_CUR_MAX with
an external variable __mb_cur_max (impacts libX11 and various ports).

* use mbstate in all the mb <-> wchar functions with state.
* add a stub iswctype function allowing some ports to compile.

bash and gdiff are missing wcscoll, and need to be told there's no i18n
until this is fixed.

Discussed and matthieu, otto, millert, kettenis, deraadt.

Major libc bump

introduce some wchar functions (from citrus and an itojun@ diff)
okay deraadt@, cloder@, pvalchev@
thanks to everyone who commented on that.

Remove the advertising clause in the UCB license which Berkeley
rescinded 22 July 1999. Proofed by myself and Theo.

NULL is now 0L so it is the same size as a pointer.
OK mickey@ and discussed with deraadt@

In ANSI C++, wchar_t is a builtin. gcc 2.95.1 handles that correctly.
Redefining it as a typedef is an error, as it prevents overloading
on e.g., int/wchar_t separately.

Define NULL to be __null for C++: better quality of implementation.
__null is a magic constant of integral type that converts to a null pointer
as should be, but warns for ambiguity when used to resolved an overload
between an integral type and a pointer type.

Well, as we are heading for a release people are encouraged to rebuild their
entire trees for testing anyway, I might as well do this intrusive touching
of include files now. Added openBSD tags.

branches: 1.1.1;
Initial revision