Reworked base_button,base_searchbutton,base_checkbox,base_spinbox,base_selector
and base_textedit to closer match the new semi transparent select bar used in
base_button_list,base_list and base_list_state.

modified:   base.xml
modified:   game-ui.xml
modified:   music-ui.xml
modified:   osd.xml
modified:   osd.xml.alt
modified:   schedule-ui.xml
modified:   video-ui.xml