fix possible error in getJstringSet
delete global variable used local referance in jni
change android sdk to 1.6.4
change Android.mk
add in JPushCallbackHelper.java
complated mianActivity
python脚本，增加xml比较函数，用来比较android manifest文件
fix build in libs and delete our libjpush164.so
add /'how update/' in document
升级jpush ios sdk v1.8.1，支持ios 8
文档升级
fix install document