This class can check if you can connect to a server.
It can take the network address of a server and the name of a protocol and it tries to establish a TCP connection to a given port of the server to see if it accepts the connection.
The server port to connect is configurable but it can also use the pre-defined ports for several known protocols like IMAP, POP3, SMTP, SMTP/TLS, SMTP/SSL, HTTP, HTTPS, FTP, CUPS, LDAP, LDAP/SSL, MYSQL, and PostreSQL.
