Clearly shows that metrics have to be explicitly sent

[C-Duv]

By looking at the usage example, one could think metrics are immediately sent to servers when calling Client::increment(), Client::count()... which is not the case: client must be explicitly asked to send data to servers.

By adding a call to Client::send() I make it clear that Client won't send data unless asked to.

[C-Duv]

It's a small thing but it took me some looong minutes to understand why my server stayed empty ;)

[omansour]

txs @C-Duv