Add string_size function
添加string_size函数

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>
using string_size instead of base class member function calling
使用string_size替代直接使用基类成员函数

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>
Update dumpImageSize version to 1.1.6.7
更新dumpImageSize版本到1.1.6.7

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>
Merge branch 'dev-2'

Signed-off-by: Wanpeng Song <swpustc@mail.ustc.edu.cn>