Make a main-loop object with associated helper functions to handle async
methods.
rtloop -> data_loop
Handle async results a lot better.
Remove REMOVE_MEM command. We don't need it.
Handle stream memory updates better.
A port is an input or output on a Node.
Channels are created from the ports and inherit the direction of the
port.
do automatic port selection based on the direction and caps and
node/port name.
Simplify stream_connect by passing the direction.
Fix pinossink to connect in setcaps so that we know the format and can
select a good sink to connect to.
