Changes with Apache 2.3.0
[ When backported to 2.2.x, remove entry from this file ]
+ *) ap_cache_cacheable_headers_out() will (now) always
+ merge an error heaeders _before_ clearing them and _before_
+ merging in the actual entity headers and doing normal
+ hop-by-hop cleansing. [Dirk-Willem van Gulik].
+
*) cache: retire ap_cache_cacheable_hdrs_out() which was used
for both in- and out-put headers; and replace it by a single
ap_cache_cacheable_headers() wrapped in a in- and out-put