SOLR-4515: CurrencyField's OpenExchangeRatesOrgProvider now requires a ratesFileLocation init param, since the previous global default no longer works (merge r1451818)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_4x@1451821 13f79535-47bb-0310-9956-ffa450edef68