添加针对所有人的群发属性

参考：http://mp.weixin.qq.com/wiki/15/5380a4e6f02f2ffdc7981a8ed7a40753.html
#.E6.9F.A5.E8.AF.A2.E7.BE.A4.E5.8F.91.E6.B6.88.E6.81.AF.E5.8F.91.E9.80.8
1.E7.8A.B6.E6.80.81.E3.80.90.E8.AE.A2.E9.98.85.E5.8F.B7.E4.B8.8E.E6.9C.8
D.E5.8A.A1.E5.8F.B7.E8.AE.A4.E8.AF.81.E5.90.8E.E5.9D.87.E5.8F.AF.E7.94.A
8.E3.80.91