[MAJOR] replace ultree with ebtree in wait-queues

The ultree code has been removed in favor of a simpler and
cleaner ebtree implementation. The eternity queue does not
need to exist anymore, and the pool_tree64 has been removed.

The ebtree node is stored in the task itself. The qlist list
header is still used by the run-queue, but will be able to
disappear once the run-queue uses ebtree too.
diff --git a/src/client.c b/src/client.c
index 06a8ce1..96c3a0a 100644
--- a/src/client.c
+++ b/src/client.c
@@ -155,9 +155,7 @@
 		if (p->options & PR_O_TCP_NOLING)
 			setsockopt(cfd, SOL_SOCKET, SO_LINGER, (struct linger *) &nolinger, sizeof(struct linger));
 
-		t->wq = NULL;
-		t->qlist.p = NULL;
-		t->state = TASK_IDLE;
+		task_init(t);
 		t->process = process_session;
 		t->context = s;
 
@@ -410,8 +408,6 @@
 			tv_bound(&t->expire, &s->txn.exp);
 		}
 
-		task_queue(t);
-
 		if (p->mode != PR_MODE_HEALTH)
 			task_wakeup(t);