Basic implementation of import.
import works for simple cases. Still work to do on finding the right
script, and setting globals/locals correctly when running an imported
function.
diff --git a/py/lexerunix.h b/py/lexerunix.h
index d86f202..b422a43 100644
--- a/py/lexerunix.h
+++ b/py/lexerunix.h
@@ -1,2 +1,4 @@
mp_lexer_t *mp_lexer_new_from_str_len(const char *src_name, const char *str, uint len, bool free_str);
mp_lexer_t *mp_lexer_new_from_file(const char *filename);
+
+void mp_import_set_directory(const char *dir);