fix incorrect bindings in curl.c3l library:

- missing `curl_` prefix for unescape
- incorrect binding for global_cleanup
- incorrect binding for global_sslset

libraries/curl.c3l/curl.c3i

@@ -1355,12 +1355,12 @@ fn char* version() @extern("curl_version");
 fn char* easy_escape(Curl* handle, char* string, int length) @extern("curl_easy_escape");
 fn char* escape(char* string, int length) @extern("curl_escape");
 fn char* easy_unescape(Curl* handle, char* string, int length, int* outlength) @extern("curl_easy_unescape");
-fn char *unescape(char* string, int length) @extern("unescape");
+fn char *unescape(char* string, int length) @extern("curl_unescape");
 fn void free(void *p) @extern("curl_free");
 fn CURLcode global_init(long flags) @extern("curl_global_init");
 fn CURLcode global_init_mem(long flags, Curl_malloc_callback m, Curl_free_callback f, Curl_realloc_callback r, Curl_strdup_callback s, Curl_calloc_callback c) @extern("curl_global_init_mem");
-fn void global_cleanup() @extern("unescape");
-fn CurlSslset global_sslset(Sslbackend id, char* name, Ssl_backend ***avail) @extern("unescape");
+fn void global_cleanup() @extern("curl_global_cleanup");
+fn CurlSslset global_sslset(Sslbackend id, char* name, Ssl_backend ***avail) @extern("curl_global_sslset");
 fn Slist *slist_append(Slist *list, char* data) @extern("curl_slist");
 fn void slist_free_all(Slist *list) @extern("curl_slist_free_all");
 fn libc::Time_t getdate(char* p, libc::Time_t *unused) @extern("curl_getdate");