Add weak_fn
Remove obsolete get_pointer
Throw if rippled.cfg is missing a [server] section
Better logging when opening Server ports.
Overlay improvements and bug fixes:
PeerImp::detach had a default argument graceful=true which did not
correctly close the socket and cause the Overlay to often hang on exit.
The logging for Overlay and Peers has been reworked. All the socket activity
is logged to Peers while protocol activity goes to Protocol. Every log line
is prefixed by a small integer ID unique to the connection.
* Removed graceful PeerImp::detach option
* Peer and Protocol log message handle respective types of logging
* Log messages prefixed with peer unique integer
* Prevent call to timer ancel from throwing an exception