Cleanup the API examples and add more docs.

apache2/api/mod_tfn_reverse.c

@@ -7,8 +7,10 @@
 #include "ap_config.h"
 #include "apr_optional.h"
 
+/* Must be declared if modsecurity.h is not included */
 APR_DECLARE_OPTIONAL_FN(void, modsec_register_tfn, (const char *name, void *fn));
 
+
 /**
  * This function will be invoked by
  * ModSecurity to transform input.