Provides macros for properly exporting or importing symbols from shared
libraries.

## Macros

### SB_EXPORT

Specification for a symbol that should be exported when building the DLL and
imported when building code that uses the DLL.

### SB_EXPORT_PRIVATE

Specification for a symbol that should be exported or imported for testing
purposes only.

### SB_IMPORT

Specification for a symbol that is expected to be defined externally to this
module.