Currently, we use DataOutput.writeUTF() for all sorts of strings. This is implemented inefficiently and potentially uses more than 1 byte per char.
Add another method writeString() which converts double byte chars to single byte chars so that only ASCII is supported. This can be used by a lot of internal code which never uses chars above 128.
For external code, such as JChannel.connect(String cluster_name), we need to see whether this is ok. Since cluster names are mainly used to differentiate clusters, perhaps it is ok to mangle the names to chars below 128, although this would change cluster names which use multi-byte chars.