ソースを参照
Don't import boostbook. The reason is that importing toolset module makes
Boost.Build believe the module is property loaded, but without 'init' call,
the module will not work. In this case, if doxygen is configured but
boostbook is not, it causes strange errors.
This commit temporary breaks doxygen -- I'm gonne fix that in a minute.
[SVN r21954]
Vladimir Prus