In order to send channel messages, we need to set a different target
than the user himself. This patch adds a new parameter `to` to the
`sendMsg()` function of the user object and allows to provide a string
as target.
This uses by default the user's nickname as target, which makes the
parameter optional and doesn't break the existing interface.
This change removes server object interacting with an internal variable
from the user object creation and reduces the amount of code from 3 to 1
line. This also simplifies future testing.
IRC is specified to have `\r\n` at the end of each command. If not
messages are not considered complete.
This patch fixes our implementation to answer with real command aka.
things that end with `\r\n`.