* detail::read_size_helper is removed
* public function read_size helps determine the optimum
size for calls to a DynamicBuffer's prepare function.
* special case for Asio types which don't conform to
the concept but have their own helper function.
fix#440
WARNING
multi_buffer constructor now takes a maximum size instead of the
"allocation size". This is a breaking change. The allocation size
feature is removed. To update calling code, remove the allocation
size parameter from call sites.
* multi_buffer now uses a geometric growth algorithm for better performance.
A new function, buffers(), returns an implementation defined object
which wraps a ConstBufferSequence and supports formatting to a
std::ostream.
The function to_string is removed, as the new implementation allows
conversion to string using boost::lexical_cast on the return value
of the call to buffers(). Streaming to an output stream is more
efficient: no dynamic allocations are performed.
Example:
streambuf sb;
std::cout << buffers(sb.data()) << std::endl;
