ToDo ...
fix some compile error with mingw
serialization only can build in msvc
Add namespace cstdint; Fix lexical_cast to lexical_cast_noexcept
bexio and nonblocking_circularbuffer
nonblocking_circularbuffer extract buffers
rename session
layer meta functions
charactor set converion
bexio:
    server
    client
    session
    protocol

charset_cvt:
    use boost.locale.conv
bexio and test_bexio
Bexio is ready test, but compiler always crash!
fixed for gcc
bexio compile ok
bexio async_connect
bexio connections count over 60000