Fix multi find_package change ${Boost_LIBRARIE} 

using boost>=1.54 with cmake on windows.

When FIND_PACKAGE(BOOST ...) is run, it overwrites the previous ${Boost_LIBRARIES} with its own required libraries

http://stackoverflow.com/questions/19720639/handling-multiple-find-package-calls-in-cmake
Merge pull request #7 from HackFisher/phoenix

Fix multi find_package change ${Boost_LIBRARIE}