Fixed compilation under MSVC(11)
- compile both libs with /UNICODE and /MP
- moved shared flags & defines to root CMakeLists.txt
- fixed resolving EXTERNAL_LIBCLANG_PATH on Windows
- postbuild copy of libclang.dll
- change PATH_TO_LLVM_ROOT & EXTERNAL_LIBCLANG_PATH to PATH variables instead of BOOL options (for cmake-gui)