LSB defines cups types that are going private

[Jeff Johnson]

Several cups types have effectively vanished from upstream.

An extract from cups/ipp.h describes this situation to some extent
(pasted after this commentary). It seems in most cases the type named
by LSB is not even present any longer, it has been replaced by an
underscore version.

The basic set of "problem" types is:

ipp_value_u
ipp_value_t
ipp_request_u
ipp_request_t
ipp_attribute_s
ipp_attribute_t
ipp_s

Of these, only ipp_attribute_t is used anywhere in the cups headers. That
is the one type that is still defined in more modern cups, devchk reports
it a problem because upstream now defines it as a typedef to a type
listed as private (_ipp_attribute_s).

Is there anything we should do to accomodate this change? LSB does not
pretend to refer to a really modern cups, and we do not have a way to
deprecate types, but most of the types don't even seem necessary to have
exposed since there are no other references to them.

===
/*
 * The following structures are PRIVATE starting with CUPS 1.6/OS X 10.8.
 * Please use the new accessor functions available in CUPS 1.6 and later, as
 * these definitions will be moved to a private header file in a future
release.
 *
 * Define _IPP_PRIVATE_STRUCTURES to cause the private IPP structures to be
 * exposed in CUPS 1.6. This happens automatically on OS X when compiling for
 * a deployment target of 10.7 or earlier.
 */
...
typedef union _ipp_request_u /**** Request Header ****/
{
...
} _ipp_request_t;

typedef union _ipp_value_u /**** Attribute Value ****/
{
...
} _ipp_value_t;
typedef _ipp_value_t ipp_value_t; /**** Convenience typedef that will be
removed @private@ ****/

struct _ipp_attribute_s /**** Attribute ****/
{
...
};

struct _ipp_s /**** IPP Request/Response/Notification ****/
{
...
};