chgserver: mangle server address to include confighash Before this patch, chgserver will use the address provided by the client. The new design is one server per confighash. This patch appends "-$confighash" to the address the client provides. To maintain the compatibility and make sure the client can connect to the server, a symbolic link is created at the original address pointing to the new address. The address is intentionally mangled at the server, instead of being pre- calculated by some other process (eg. a previous server). In this way, we can avoid file system race conditions.