Account for possible null data for Date field types.

In the case that no data was entered for a Date type field,
crashes would occur when calls to convertStringToDate were made.
Merge pull request #10 from BrightcoveConsultingReusableComponents/null-date-fix

Account for possible null data for Date field types.
Merge pull request #11 from BrightcoveConsultingReusableComponents/development

Pull latest dev change into Master