QAMQP::Frame used to be public API mostly for MessageProperties. There
is no longer a need to keep this API public, as it should all be wrapped
with the cleaner Message/Queue/Exchange/Client API set
MessageProperties is currently defined in Frame::Content, which makes it
cumbersome to use when working directly with a Message itself. I attempted
to make this easier by using typedefs, but it's become pretty obvious that
it belongs in the Message class itself.
Matt Broadstone