Add reconnecting event and relevant test

[poohlt]

@guille A pull request to make a Manager emits 'reconnecting' event when trying to reconnect. Also a test case is included :)

[rauchg]

@poohlty we need to emit the reconnection events on the sockets, not the manager.

[rauchg]

Aka if you do

var socket1 = io('/a');
var socket2 = io('/b');
socket2.disconnect();

And then you lose connection, socket1 should emit reconnecting but socket2 shouldn't.

[rauchg]

Also, there are conflicts that prevent this from being mergeable. Same with the other pull request on socket.io

[poohlt]

Ah, make sense. How do I know when the socket should emit 'reconnecting' though? It seems to me that the reconnecting logic is handled by a manager, which is hidden to a socket?

[poohlt]

@guille do I need more updates on this?

[rauchg]

Since this is not public API, i'd rather us test by forcing a disconnetion, and expecting a reconnection.

[poohlt]

@guille Now the test closes the engine rather than calling reconnect :)