application.dialogs.ConflictDialog: Conflict Dialog
This implements the spec as set out in http://chandlerproject.org/Journal/NoDataLossProposal
specifically, the image:
http://chandlerproject.org/pub/Journal/NoDataLossProposal/No_data_loss_pop-up_Three.png
The blue background colours are still unimplemented.
application.styles: This is an experiment in light weight "styles", i.e.,
configuration read from a file, with the aim of making it easy for
the design team to tweak graphical details without mucking about in
Python.