MONROVIA, Liberia — Liberians gathered in masses under the bright sun Tuesday to vote in an election that for the first time in more than 70 years will see one democratically elected government hand power to another. As Africa’s first female president prepares to step aside, there are fears that if the results aren’t accepted the tensions and violence of Liberia’s past could rise again. “This election now is crucial and important because as you can see the peace is very fragile right now and we need a smooth transition from one government to another,” said Stevera Toh, a 32-year-old accountant.