Edited close() method of the class, to force the EventLoops associated to netty channels to be shutdown. This is an important update, since it fixes a very old memory leak that prevented file descriptors from being released, even if the Netty channels were explicitly closed using TOMSender.close().

Fixed small bug on LCManager.hasValidProof(...). It would return 'false' if at least one of the messages was invalid.

.class and .jar files already udpated within this commit.

Undone modification done in commit 2079febd (it would make the protocol incorrect)

Update NettyClientServerCommunicationSystemClientSide.java

Fixed quorum size computation

Fixed a bug related with unreleased Netty thread resources at the client side.

The division between two integers returns an integer (loss of precision) thus giving incorrect results for the quorum size.

Fixed a bug in the AsynchServiceProxy class that would case a race condition between the client and the servers: the client would store its sequence number after sending its requests, but if the servers responded quickly enough for the client to parse the replies before storing the sequence number, the messages would be discarded.

Also edited a logging message and added another one.