Fold debugger monkey patching into Theme

[M Bussonnier]

debugger code contains:

        cst = self.color_scheme_table

        cst['NoColor'].colors.prompt = C.NoColor
        cst['NoColor'].colors.breakpoint_enabled = C.NoColor
        cst['NoColor'].colors.breakpoint_disabled = C.NoColor

        cst['Linux'].colors.prompt = C.Green
        cst['Linux'].colors.breakpoint_enabled = C.LightRed
        cst['Linux'].colors.breakpoint_disabled = C.Red

        cst['LightBG'].colors.prompt = C.Blue
        cst['LightBG'].colors.breakpoint_enabled = C.LightRed
        cst['LightBG'].colors.breakpoint_disabled = C.Red

        cst['Neutral'].colors.prompt = C.Blue
        cst['Neutral'].colors.breakpoint_enabled = C.LightRed
        cst['Neutral'].colors.breakpoint_disabled = C.Red

Is should be just move to where the colors are defined.