Popup refactor

1. Move all style properties to widget.tss
2. Create close button dynamicaly to make widget more independence
3. Cleanup
closeButton' is **button** for me firstly. UI.Button, UI.View, ti.ux.iconbutton or something like that. External interface must be maximum understandable without documentation. Four letters are not significant. If next time you want add the ability to set close button from options then you will get name conflict. Anyway this option didn't work until today so we have a chance to change it now. But not tomorrow. Bad code is better than bad external interface. First you can change any time but last very rarely.