- each module now has a version, eg IMP::get_module_version_info() which is also returned by the various restraints of the module. The python code checkes that loaded libraries have the expected version numbers to try to provide better messages when errors in path link result in linking against the wrong version of IMP.

- the various ::bounding_box() methods have been renamed to ::get_bounding_box() to be more consistent with the other names.

- python documentation is now parsed by doxygen