v2.0.0-alpha2

SetText/GetText优化 (#12)

* SetTextA/GetTextA, in-progress

* Unnececcary + 1

* DUIRichEdit::GetLineText, 确保当字符小于sizeof(int) -1 时，分配足够空间，避免踩无效内存

* 优化，避免不必要的buffer深拷贝

* Use external to manage dependeicies

* 利用函数重载

* fix vs2013 compile issue

* 避免不必要的强转

* Add c++ standard choose support, _CXX_STD=17

* C++17 compiler support

* Implement DM::CStringW to std::string for ntcvt

* Explicit match c style string

* Rename name

* Define WIN32_LEAN_AND_MEAN