Building with MinGW attempts to link to Boost.

[SteveCookTU]

Following the getting started page, I generated the build file contents using cmake -G "MSYS Makefiles" ... Used the MSYS generator because I am using MinGW64 from within MSYS.

Upon running make, it all performs as expected until it reaches linking to the executable. It fails to link to items in the boost::thread namespace. Looking at the CMakeLists.txt in the repo, I know I do not have Boost_FOUND predefined and pthreads is successfully found.