* When reading XML with namespace processing enabled, create 'level 2' elements and attributes even if their namespaceUri is empty.
* dom.pp: fix bug uncovered by above change. Non-empty prefix cannot be set not only for 'level 1' nodes, but for level 2 nodes with empty namespaceUri, too.
- xmlwrite.pp: workaround for parser behavior no longer necessary, removed.

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@24315 3ad0048d-3df7-0310-abae-a5850022a9f2