Make use of a running GPA server.
* src/server.c (cmd_start_clipboard): New. (cmd_start_filemanager): New. (register_commands): Add new commands. (cmd_getinfo): Add sub-command "name". (check_name_cb, gpa_check_server, gpa_send_to_server): New. * src/gpa.c (option_entries): Add option --no-remote. Remove options --gpg-binary and --gpgsm-binary. (struct gpa_args_t): Add no_remote. Remove gpg_binary and gpgsm_binary. (dummy_arg): New. (main): Check for running server and start if desired. Factor some code out to ... (open_requested_window): new. Add code to connect to a running server.