- Use *Gui.{FgColor,BgColor} to set GUI's color.
- Use *Gui.{SelFgColor,SelBgColor} to set current view's color.
- Drop *Gui.ActiveColor and *View.ActiveColor.
- Full mouse support based on hazbo's initial work.
- Add example to show mouse support.
- Fix comments, naming conventions, etc. to make golint happy.