message: Explicitly mark `binary_deserializer` as exported
  For some reason CMake auto DLL exports generator + VS compiler won't
  make `binary_deserializer` vftable visible in `caf_core.dll` which in
  turn cause `caf_io.dll` linking error.
  Add workaround that works, but produces bunch of C4275 warnings
  (can be ignored because everything gets exported anyway).
diff: namespace caf {
  /// Implements the deserializer interface with a binary serialization protocol.
  -class binary_deserializer final : public deserializer {
  +class CAF_API binary_deserializer final : public deserializer {
  public:
  // -- member types -----------------------------------------------------------
  