added <format>pdf: to XEP and FO items to make it build pdf.

Without gave
[error] There can be only one 'rx:outline' element as a child of 'fo:root'.

[SVN r67917]

libs/chrono

@@ -1 +1 @@
-Subproject commit 357a9c6a4376428fd860942e94430be9f0d1af74
+Subproject commit 4ad7cd90d2600ddbe7305a68e0ba91c77eb4eb7c