修改：delay 延时支持延时变更、取消事件

git-svn-id: svn://47.119.165.148/zhub@95 e63fbceb-bcc3-4977-ac22-735b83d8d0f4

zsub/zsub.go

@@ -7,12 +7,14 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"time"
 )
 
 var (
 	zsub = ZSub{
 		topics: make(map[string]*ZTopic),
 		timers: make(map[string]*ZTimer),
+		delays: make(map[string]*time.Timer),
 	}
 )
 
@@ -20,6 +22,7 @@ type ZSub struct {
 	sync.RWMutex
 	topics map[string]*ZTopic
 	timers map[string]*ZTimer
+	delays map[string]*time.Timer
 }
 
 type ZConn struct { //ZConn