__STL_NO_NAMESPACES is wrong

[Paul J. Lucas]

	In stl_config.h, there is a section that defines a bunch of
	stuff for the g++ compiler (#ifdef __GNUC__).  For recent
	versions, it incorrectly (in my opinion) defines __STL_NO_NAMESPACES
	(this despite the fact that it also defines __STL_HAS_NAMESPACES).

	The __STL_NO_NAMESPACES flag is supposed to be user-defined
	only, yet it's defined by the header and there is no way for the
	user to undefine it (short of editing the header file.  (It's
	also defined incorrectly for _MSC_VER).

	One consequence of this is that std::iterator doesn't get
	defined.  I saw that this has been a known problem since at
	least late 1999 (from another mailing list's archives).

	Shouldn't this be fixed?  Simply removing all definitions of
	__STL_NO_NAMESPACES does it.

	- Paul