Adding missing header to build with Boost 1.55.0
Changing HTTP message content length type from uint64_t to size_t in order to eliminate Visual C++ 2010 warnings for 32-bit targets
Fixing Visual C++ warning C4800: 'uint8_t' : forcing value to bool 'true' or 'false' (performance warning)
Added missing const qualifier for endpoint argument in a tcp::connection::async_connect() function overloading
Merge branch 'develop' of git://github.com/pmed/pion into develop