mifosx-567 add support for externalId for loan transactions
Merge pull request #503 from johnw65/externalIds

mifosx-567 add support for externalId for loan transactions
Raman - Fixed defect for java 1.6.
Null checks for collection sheet get data
Merge pull request #504 from mifoscontributer/MIFOSX-310

Null checks for collection sheet get data