Adding missing "extern" from SEXP_API definition. Fixes issue #197.
Adding missing "extern" from SEXP_API definition.
Fixes issue #197.

holmescn/chibi-scheme,holmescn/chibi-scheme,holmescn/chibi-scheme,holmescn/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme,holmescn/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme,norton/chibi-scheme