Customizable Chat Style/Colors

[snade]

* New Tab at OptionDlg? (Chat Tab) * CMessageViewWidget with new overloaded addMsg: This method has many parameters, and the html appended to it is customizable accordingly to some CMainWindow public attributes (m_nMsgStyle; m_bAppendLineBreak; m_colorXXX). It would be nice if m_nMsgStyle was type enumerated) * CHistoryWidget is a superclass of CMessageViewWidget. So i have changed UserInfoDlg? in order to use a CMessageViewWidget in the place of CHistoryWidget. This change make the history style also customizable. I really didn't like that. * If we change the style, the new style isn't applyied to opened chats.