Added methods `HasProperty` and `HasValue`
Added methods `HasProperty` and `HasValue`

Added methods to the `Fieldset` object for checking if a property exists and/or if it has a value.

tomfulton/Archetype,Nicholas-Westby/Archetype,kjac/Archetype,kgiszewski/Archetype,imulus/Archetype,kipusoep/Archetype,kjac/Archetype,kipusoep/Archetype,Nicholas-Westby/Archetype,imulus/Archetype,kjac/Archetype,tomfulton/Archetype,imulus/Archetype,tomfulton/Archetype,kgiszewski/Archetype,kipusoep/Archetype,kgiszewski/Archetype,Nicholas-Westby/Archetype