Merge feat/p5-remote-option: --remote-option, --trust-sender

# Conflicts:
#	RSYNC_COMPAT.md
#	src/client/client_cli.c
#	src/client/client_send.c
#	src/shared/transport_ssh.c
#	src/shared/transport_ssh.h
#	tests/integration/test_ssh.py
#	tests/test_client_cli.c
#	tests/test_transport_ssh.c

src/shared/transport_ssh.h

@@ -4,8 +4,15 @@
 #include "transport_tcp.h"
 
 Client* client_connect_ssh(const char* destination, int port, const char* server_path,
-                           bool old_args, const char* rsh_command, bool blocking_io);
-char* ssh_build_remote_command(const char* server_path, bool old_args);
+                           bool old_args, const char* rsh_command, bool blocking_io,
+                           char* const* remote_options, int remote_option_count);
+/* Build the escaped remote-shell command string (the server program path quoted
+ * as one remote-shell word unless --old-args, followed by ` --stdio` and each
+ * --remote-option value appended as an individually single-quoted shell word).
+ * Every --remote-option value is individually escaped with the '\'' sequence and
+ * values with empty/control characters are rejected at the CLI parse layer. */
+char* ssh_build_remote_command(const char* server_path, bool old_args, char* const* remote_options,
+                               int remote_option_count);
 /* Build the NULL-terminated child argv for the remote-shell client (argv[0] is
  * the exec/execvp program).  rsh_command is whitespace-split into leading argv
  * words (NULL or "" selects the default "ssh"); the standard -o family, the