WIP: Reworked slicing

1) Slicing code moved to TriangleMeshSlicer.cpp,hpp from TriangleMesh.cpp,hpp
2) Refactored to use as little as possible of admesh.

src/slic3r/Utils/FixModelByWin10.cpp

@@ -27,6 +27,7 @@
 #include <boost/filesystem.hpp>
 #include <boost/nowide/convert.hpp>
 #include <boost/nowide/cstdio.hpp>
+#include <boost/thread.hpp>
 
 #include "libslic3r/Model.hpp"
 #include "libslic3r/Print.hpp"