Major change to sequencer API.

The sequencer API is totally recoded with the style of "encapsulation"
in other api.
The structure becomes opaque and accessed only via functions.

Other changes:
- There is no longer group in client and port info.
- snd_seq_query_subs_t is renamed to snd_seq_query_subscribe_t.
- snd_seq_delete_port takes only the port id argument instead of
  port_info structure.
- snd_seq_input/output_buffer_size are renamed
  as snd_seq_get_input/output_buffer_size.
  Similarly snd_seq_resize_input/output_buffer are renamed as
  snd_seq_set_input/output_buffer_size.
- snd_seq_get_named_queue is renamed to snd_seq_query_named_queue.
- Sync codes are removed temporarily from API.
- Subscription conditions are accessed via the corresponding functions.
  convert_time is named now as time_update.
- snd_seq_get/set_queue_owner are removed.
  Use snd_seq_get/set_queue_info instead.
- Instrument put/get/remove structure is unified as snd_instr_header_t.

include/Makefile.am

@@ -7,7 +7,7 @@ header_files=header.h version.h global.h input.h output.h error.h \
 	     conf.h pcm.h rawmidi.h timer.h \
 	     hwdep.h hwdep_m4.h control.h \
 	     mixer.h \
-	     seq.h seqmid.h seq_midi_event.h \
+	     seq_event.h seq.h seqmid.h seq_midi_event.h \
              conv.h instr.h footer.h
 
 noinst_HEADERS=$(header_files) search.h list.h aserver.h local.h