Infer filename from content-disposition or URL

The Content-Disposition inferring is probably a bad idea security wise,
so I am going to remove it.

src/tools/http_download.h

@@ -48,6 +48,8 @@
 
 typedef struct http_download_t {
     char *url;
+    char *filename;
+    char *directory;
     FILE *filehandle;
     curl_off_t bytes_received;
     ProfWin *window;
@@ -60,4 +62,7 @@ void* http_file_get(void *userdata);
 void http_download_cancel_processes(ProfWin *window);
 void http_download_add_download(HTTPDownload *download);
 
+char *http_filename_from_url(const char *url);
+char *http_filename_from_header(char *header);
+
 #endif