CLIENTAPI

Describes our client API.  


Communication from child process to parent process:

* get_connection_status (child_id) - gets the status of a connection. 
    -param int child_id: the ID of a child process who's client connection we
     want to get the status of

    -return conn_state_t: The state of the connection.  Possible values are:

        CONN_CONNECTION - the connection is normal and stable
        CONN_DISCONNECTED - there is no client connection
        CONN_SENDING - the child process is sending a message to the client
            which has not completed yet, but the send operation was not
            blocking.
        CONN_RECVING - the child process is receiving a message from the client
            which has not completed yet, but the receive operation was not
            blocking.
        CONN_CLOSING - the connection is being closed.  The command which
            triggers this state requires the server to send a message to the
            client, then requires a client response before closing the
            connection.  This state happens while either the message is being
            send, or received.
        CONN_TERMING - the connection is being terminated without the parent <->
            child exchange.
        CONN_RESET - the connection is attempting to be reset.  This state
            happens before it is certain whether the reset succeeded or not.
        CONN_WAITSEND - the server is sending a message to the client and is
            blocked until the operation completes.
        CONN_WAITRECV - the server is receiving a message from the client and is
            blocked until the operation completes.

* get_conn_info (child_id) - gets information about a child and its client
    -param int child_id: the ID of a child process who's connection information
     we want

    -return proc_info_t: The information about the process, returned in a
     struct:

        struct proc_info
        {
            int proc_id;        // server ID of the process, NOT the system pid
            ip_addr_t client_ip;    // The client's ip address
            conn_state_t conn_state;// the state of this process's connection
            struct proc_info* next; // used to access a list of all processes
        };
        typedef struct proc_info proc_info_t;