Instead of setting up the default keys by building the key struct

directly with a helper function in the cmd_entry, include a table of
bind-key commands and pass them through the command parser and a
temporary cmd_q.

As well as being smaller, this will allow default bindings to be command
sequences which will probably be needed soon.

cmd-send-keys.c

@@ -34,7 +34,6 @@ const struct cmd_entry cmd_send_keys_entry = {
 	"lRt:", 0, -1,
 	"[-lR] " CMD_TARGET_PANE_USAGE " key ...",
 	0,
-	NULL,
 	cmd_send_keys_exec
 };
 
@@ -43,7 +42,6 @@ const struct cmd_entry cmd_send_prefix_entry = {
 	"2t:", 0, 0,
 	"[-2] " CMD_TARGET_PANE_USAGE,
 	0,
-	NULL,
 	cmd_send_keys_exec
 };