[xml] Compressed Documents

["William M. Brack" <wbrack mmm com hk>]

I'm working on a bug report
(http://bugzilla.gnome.org/show_bug.cgi?id=120503), and would to ask
for further input from the list.

The reporter has pointed out that the compression mode of the input
document can be important to the library user, and without knowing
it the output mode of a document may not match the input.  At the
moment, the library does not set the compression (i.e.
xmlSetDocCompression is not called by any routine within the
library).