Add interface to get internal structures for classes
Stop using StringVectorPtr

Use vector<string> instead, because there is no need to use a shared_ptr to maintain a vector
Add missing headers
Stop using DictEntryPtr
Add std::string interface for Dict
Fix single character conversion in Simplifier

upgrade opencc to 22f8c927296486c8fffc5e8ac181a9e337d395cd
Merge commit '22f8c927296486c8fffc5e8ac181a9e337d395cd' into develop
Merge remote-tracking branch 'byvoid/develop' into develop