Remove array_allocator extension, deprecated since 4.9.0

This type is not a conforming allocator, because it cannot be reliably
rebound to allocate for a different type. The result of the rebind
transformation still uses the same underlying std::tr1::array<T, 1>
array, which may not be correctly aligned or even have elements the
right size for the value_type of the rebound allocator.

It has been deprecated for several years and should now be removed.

	* doc/xml/manual/allocator.xml: Remove documentation for
	array_allocator.
	* doc/xml/manual/evolution.xml: Document array_allocator removal.
	* doc/xml/manual/using.xml: Remove header from documentation.
	* include/Makefile.am: Remove <ext/array_allocator.h> header.
	* include/Makefile.in: Regenerate.
	* include/ext/array_allocator.h: Remove.
	* include/precompiled/extc++.h: Do not include removed header.
	* testsuite/ext/array_allocator/1.cc: Remove.
	* testsuite/ext/array_allocator/2.cc: Remove.
	* testsuite/ext/array_allocator/26875.cc: Remove.
	* testsuite/ext/array_allocator/3.cc: Remove.
	* testsuite/ext/array_allocator/check_deallocate_null.cc: Remove.
	* testsuite/ext/array_allocator/check_delete.cc: Remove.
	* testsuite/ext/array_allocator/check_new.cc: Remove.
	* testsuite/ext/array_allocator/variadic_construct.cc: Remove.
	* testsuite/ext/headers.cc: Do not include removed header.

From-SVN: r271119