Improving BStringView

BStringView should be changed so that the user can select the text. This would allow the user to copy labels out of GUIs. The only good reason for not allowing the user to select this text would be if there was some other meaning to the typical select gesture. (click, drag; or click, position, shift-click) Since this view doesn't ascribe any other meaning to the select gesture, it should support the default meaning for the select gesture.

See also TextPresentationSelectionNit.