ChatBox.cs: fix 1 rare case where if user somehow able to post multi-line message in a single line & pressed Show Join-Leave-line (or pressed to disable it), then the multi-line structure will disappear.

Config.cs: explain that "Forget Password" might not work if ZKL crash

TextColor.cs: fix wrong definition for IRC Color Reset char (currently no used yet. Other place had them hardcoded independently). Its \x0f , not F

TasClient.cs: tweak error message, for more clarity