Implemented a nick compare function

As suggested by the todos in IRCSock, added IsNick(CString) method
so the ugly Nick.GetNick().Equals(GetNick()) could be simplified.

Signed-off-by: Toon Schoenmakers <nighteyes1993@gmail.com>
Renamed IsNick to NickEquals

Also added a TODO to add proper IRC case comparing.

Signed-off-by: Toon Schoenmakers <nighteyes1993@gmail.com>
Replaced the GetNick().Equals() with NickEquals() where possible

Signed-off-by: Toon Schoenmakers <nighteyes1993@gmail.com>
Merge pull request #416 from schoentoon/master

Implemented a nick compare function