APACHE_XLATE, CHARSET_EBCDIC stuff:

Provide new function ap_set_content_xlate() to simplify what needs
to be done to set up translation of content.  Use it where appropriate.

With this change, EBCDIC logic was tweaked so that ap_checkconv() does
not overlay a translation handle previously stored (e.g., by a module)
unless it is turning translation off.  Unless ap_checkconv() determines
that translation is inappropriate, it should leave the translation handle
alone.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85296 13f79535-47bb-0310-9956-ffa450edef68