Merge changes from Trunk:
* Fix common_factor code so it works with expression-template enabled types, and added new tests.
* Cleaned up using declarations.
* Fixed cbrt conceptual requirements.
* Fixed round for negative values.
* Changed all configuration code to use the new Boost.Build configuration support.
* Fixed HP aCC version numbers in src files.
* Regenerated docs.
[SVN r62124]
John Maddock