director: Make director_host_cmp_p() public

director: Add director_host.ip_str This avoids having to use net_ip2addr() all the time to convert it into a string.

director: If SYNCs are received during handshake, send them later. This fixes delays during handshake: Error: Ring SYNC appears to have got lost, resending

global: unsigned int:1 -> bool:1 perl -i -pe 's/unsigned int ([^,:;]+):1;/bool $1:1;/' **/*.[ch]

director: Detect if directors' hosts have become desynced by sending hosts_hash in SYNC parameter. Also fix up such a situation by resending all HOSTs.

Changed type of internet port values to in_port_t everywhere. Created special SET_IN_PORT setting type for internet port values. Created net_str2port() for parsing internet port values. Removed several atoi() invocations in the process.

director: Reset last-seen-sync-sequence after remote director restarts.

director: Avoid infinite SYNC loops if the originating director goes away for a long time.

Renamed network.[ch] to net.[ch]. The function prefixes already started with net_ instead of network_. And icecap wants to use network.h for other purpose. :)

director: Implemented ability to remove directors from a running ring. Also added doveadm command for adding a new director to a running ring.

director: Don't communicate with directors that recently sent invalid input. Track network and protocol failures separately. If a director had sent invalid protocol data within last 60 seconds, don't try to connect to it and don't allow it to connect to us.

director: Lots of fixes. It should be pretty stable now. --HG-- branch : HEAD

director: Handle CONNECT commands (properly). --HG-- branch : HEAD

director: If connecting to director fails, try connecting to next one. --HG-- branch : HEAD

Added initial implementation of a director process (for NFS users). There are still some unimplemented features and bugs. Also changing mail server list doesn't yet make sure that other directors won't assign the same user to a different server at the same time. --HG-- branch : HEAD