Use generic extensible URI identifiers in the config file instead of current bind_address/port

Today, to specify IP address and ports to connect to in the configuration file, one has to set the following:
bind_address = 127.0.0.1
admin_port = 33013

This scheme has the following shortcomings:
- there is no way to specify the desired transport (e.g. ssl).
- each protocol requires its own port
- there is no support for DNS
- there is no support for UNIX sockets or other transport mechanisms.

We need a scheme which allows to specify:
- multiple ports/transports to listen on
- an IPV6 address
- choose transport format
- use unix sockets or DNS if necessary

Something like:

listen_on = 127.0.0.1:33013/{rpl,binary,admin}
- bind to address 127.0.0.1, port 33013, support on this address/port rpl, binary and admin protocols
listen_on = auth:///tmp/tarantool.sock/{admin} - open a UNIX socket, require authenticated connection, support admin protocol only

listen_on = ssl://192.0.0.15:33015:{binary,memcached} - require ssl, bind to 192.0.0.15, support memcached protocol (memcached protocol has to be mutually exclusive with everything else, other protocols can be specified together, since we can make protocol request part of the handshake).

We'll have to perform some magic to ensure that multiple listen-to clauses do not contradict.