Support AOE config strings

[barakmich]

This gets the volume to at least be connected by the Windows AoE initiator. (Formatting still fails)

[mischief]

should maybe implement the rest of the config commands, and also reject the config if set:

CCmd 3: set config string
 If the current server config string is empty, set the server config
 string to the argument string and respond. If the current server
 config string is not empty, return a response with Flags bit E set
 and Error set to 4.

[mdlayher]

@barakmich want to rebase this one so we can try to get the server working with Windows?