Hilary Heuler KAMPALA ? The conflict in South Sudan is sending ripples across the regional economy. In Uganda, one of South Sudan#39;s biggest trading partners, tens of thousands of merchants are feeling the loss of cross-border trade. In late December, Dan Ssesanga was herded into a Ugandan military truck and, with gunfire ringing in his ears, given safe passage out of South Sudan#39;s capital, Juba. But Ssesanga sells eggs, and his merchandise stayed behind. ldquo;I left behind 600 crates of eggs -...