message: More common exports
diff: #include <string>
  +#include "export.h"
  #include "image_base.h"
  namespace visionaray
  @@ -18,13 +19,13 @@ class image : public image_base
  public:
  // Default constructor.
  - image() = default;
  + VSNRAY_COMMON_EXPORT image() = default;
  // Construct image from width, height, format, and data (data is copied).
  - image(size_t width, size_t height, pixel_format format, uint8_t const* data);
  + VSNRAY_COMMON_EXPORT image(size_t width, size_t height, pixel_format format, uint8_t const* data);
  - bool load(std::string const& filename);
  - bool save(std::string const& filename, save_options const& options);
  + VSNRAY_COMMON_EXPORT bool load(std::string const& filename);
  + VSNRAY_COMMON_EXPORT bool save(std::string const& filename, save_options const& options);
  };
  