update avhttp
判断是否打开
changelog
使用 BOOST_ASIO_CORO_REENTER 而不是简化的 reenter, 因为是头文件, 最好不要导致 yield 关键字干扰
fix No newline at end of file
add some usefull define
fix issue pointed out by jackarain
Merge pull request #4 from microcai/master

some misc update for avbot