WASHINGTON (Reuters) - Federal disclosures filed on Monday revealed new details of the sources of money raised by Republican presidential hopeful Mitt Romney for the Romney Victory fund he uses jointly with the Republican National Committee. Joint funds allow candidates to accept bigger checks than campaigns on their own. Campaigns can accept only up to $5,000 from one donor, while a fund used jointly with the national party can accept up to $70,800 in addition to that. Romney's Victory fund has reported raising a total of $375.6 million since its creation in April, and $235. ...