In 95% of cases, a plugin writer is going to want to consider empty string values for properties to be invalid. But there will be some cases where they want to allow empty strings for certain properties. To support these cases, add a allowsEmptyValue boolean option to PropertyDefinitionSimple that defaults to false.
This bug was previously known as http://jira.rhq-project.org/browse/RHQ-997
mass add of key word FutureFeature to help track