Add ability to use query param when connecting to socket.io server.

[dclause]

Merge request to add ability to use query params when connecting to socket.io

I personally use it, but it also has been requested by issue #26

To use it, simply add the query in a char array as per the hostname but url encode this string.

Example:

char query[] = "id=foo&name=bar";

Then change your usage of connect() from client.connect(hostname, port) to client.connect(hostname, port, query)

[washo4evr]

Thanks a lot, this is a great addon :)