Add jxpath extension functions:

• history:charges(patient, from, to) - returns all invoice items for a patient where startTime >= from and startTime < to

• history:charges(patient, productTypeName, from, to) - returns all invoice items for a patient with a product type name matching that specified, where startTime >= from and startTime < to. The product type name may contain wildcards

• history:charges(patient, date) - returns all invoice items for a patient done on the specified date

• history:charges(patient, productTypeName, date) - returns all invoice items for a patient done on the specified date, with a product type name matching that specified. The product type name may contain wildcards