finer sliders, curve points and a before/after key

a colourist tested the editor on a fashion shoot and sent notes. four of them are fixed.

fixes

• –sliders move by 1: dragging away from zero used to jump straight to 6, because the slider pulled back to its default anywhere within 5. it now moves freely on the way out and still lands exactly on zero on the way back
• –double-click removes a curve point: on the curves and the hue curves, as the hint under them always said
• –\ switches before and after: it now works straight after you've moved a slider. hover the before and after buttons to see it
• –bloom (glow): film effects' bloom is labelled as glow too, and search finds it under either word

his before and after, graded with tungsten 500, is now on the kodak 500t look page.