Some comments added.

=============================================================

Critical:
//TODO: implement download (send file to client interested on it)
//TODO: supernode remove client's files from hashtable
//TODO: supernode tell other supernodes to remove files

Needed:
//TODO: add better messages in classes in packages server and supernode

Bonus:
//TODO: send all files to new supernode associated (when reconnect), instead of set hashtable as new
	  Can be done on method connetc in Client.java