Initial work on Twirc.Lib.

* IRCClient.cs:
  Added very basic methods.
Added additional library functionality.

* Extensions.cs:
  Added Range() method.

* IRCClient.cs:
  Added LoggedIn field.
  Added Username field.
  Added MaxBufferSize field.
  Added VerifyLogin() method.
  Added overloaded Connect() method that will also login a user.
  Added SendLine(), ReadLine(), Logout(), and Dispose() methods.
  Implemented Login() method.
Documentation changes.
Added a few events for different phases.
Added Join() and Leave() method.
Added several more events.
Added channel tracking.
Added line processors and changed the login system to give better information. Also added a basic example of the client.

* Program.cs:
  Added sample usage of the client.

* IRCClient.cs:
  Added line handling.
  Added LoginResponse struct.
  Modified VerifyLogin() and Login() to use the LoginResponse struct.
  Added several events.
Added joining & leaving handling.

* Program.cs:
  Added OnJoin and OnLeave handlers.
  Removed limited message count handling.

* IRCClient.cs:
  Documentation updates.
  Updated JoinDel and LeaveDel delegates.
  Added separate channel catcher, so parsing JOIN's and PART's are
  possible.
  Added JOIN and PART message handlers.

* Extensions.cs:
  Added overload Range() method that can take multiple ending strings.