- Output detected version of boost in dot-form (e.g., 1.56.0, instead of 1_56)
- Fix Boost.Log library detection:
* when linking to shared library, BOOST_LOG_DYN_LINK needs to be defined
* when linking to non-multithreaded version, BOOST_LOG_NO_THREADS needs to be defined
(see http://www.boost.org/doc/libs/1_60_0/libs/log/doc/html/log/installation/config.html)
