Small refactoring of tbytevector.cpp
Merge pull request #138 from TsudaKageyu/refector-bytevector

Small refactoring of tbytevector.cpp
Small refactoring of tstring.cpp
Merge pull request #139 from TsudaKageyu/refactor-string

Small refactoring of tstring.cpp
Replace RefCounter with a smart pointer
Merge pull request #141 from TsudaKageyu/smart-ptr

Replace RefCounter with a smart pointer