Boostbook: merge changes.

Doxygen:

- Add support for verbatim (danieljames).
- Handle explicit (steven_watanabe).
- Handle description of public data members (steven_watanabe).

Fop:

- Working link to download, in setup_boostbook (garcia).
- Improved description of A4 in docs (garcia).



[SVN r70450]

tools/boostbook

@@ -1 +1 @@
-Subproject commit e6c9ba02c45c24face0f071967a0b8316b5bb593
+Subproject commit 68ed9a4d3c9783fa84872cfc0ff819e422dbc83e