QI-379 Money and BigMoney properties support using JodaMoney

EntityStores and Index/Query engines support added with tests.

EntityStores use the String form of BigDecimal serialization.
Index/Query engines use the rounded double form.

ElasticSearch Index/Query engine is the only one to support queries on
money amount and currencies. RDF and SQL indexing need some more love.
QI-379 Introduce MoneyConversion API and OpenExchangeRates.org lib