Merge branch 'main' into metadata-transfer, resolve conflicts

Conflicts resolved:
- config_create signature: added both use_metadata and use_sendfile params
- config_send/config_receive: wire protocol includes both use_metadata and use_sendfile
- client.c: config_create call updated, arg parsing includes both -M/--preserve and -f/--sendfile
- test_config.c: all three config_create calls updated
- file_send_sendfile: use file->data->size instead of removed struct stat

src/shared/config.h

@@ -11,6 +11,7 @@ typedef struct Config {
   bool use_multithreading;
   bool use_chunk_serialization;
   bool use_compression;
+  bool use_sendfile;
   bool use_single_send_per_file;
   bool use_metadata;
   int compression_level;
@@ -20,8 +21,8 @@ typedef struct Config {
 Config *config_create(char *version, char *send_directory,
                       char *receive_directory, bool save_to_disk,
                       bool use_multithreading, bool use_chunk_serialization,
-                      bool use_compression, bool use_metadata,
-                      int compression_level, int num_connections);
+                       bool use_compression, bool use_metadata,
+                       int compression_level, int num_connections, bool use_sendfile);
 void config_delete(Config *config);
 void config_send(int file_descriptor, Config *config);
 Config *config_receive(int file_descriptor);