* Republican presidential hopeful's actions unprecedented * Aides purchased hard drives of state-issued computers * Emails and other communications wiped from servers By Mark Hosenball WASHINGTON, Dec 5 (Reuters) - Mitt Romney spent nearly $100,000 in state funds to replace computers in his office at the end of his term as governor of Massachusetts in 2007 as part of an unprecedented effort to keep his records secret, Reuters has learned. The move during the final weeks of Romney's administration was legal but unusual for a departing governor, Massachusetts officials say. The effort to purge the records was made a few...