By Nell Mackenzie LONDON (Reuters) -Wealthy investors in the United States and Asia have cancelled plans to put money into U.S. hedge funds this year, while increasing their exposure to Europe and the Middle East, according to a Bank of America survey seen by Reuters on Thursday. Half of the allocators who told Bank of America last year they would invest in U.S. hedge funds have now ditched these plans, according to the survey. The report, which canvassed 263 respondents, representing around $840 bill ...