KYIV - The choice is stark. Stay the slow and not-quite-steady course with a deeply unpopular but seasoned leader who knows the ropes and has taken Ukraine westward despite foot-dragging on reforms and a failure to tackle entrenched corruption. Go with another veteran, a political survivor with a dodgy past twice imprisoned by opponents who has lost two presidential elections but is banking on public disappointment and populist promises to carry her to victory. Or take a chance on a comedian with no experience in politics and governing but who has managed to tap into an antiestablishment mood similar to...