add random string generator
Merge branch 'develop' of https://github.com/STUKA-TEAM/ZhongheWeiHelper into develop
add some lottery code
Merge branch 'develop' of https://github.com/STUKA-TEAM/ZhongheWeiHelper into develop
modify lottery
Merge branch 'develop' of https://github.com/STUKA-TEAM/ZhongheWeiHelper into develop
change to the imageutil