#118 [UWT] Implementation RefField

[Oleh Hapon]

Implementation RefField mode for following controls:
- ComboBox
- ListBox
- RadioGroup

Implementation new properties:
- ref-property
- ref-data-type

Need special format to load items from XML like this:

• Object(1, 'Name 1')

• Object(2, 'Name 2')

• Lookup(1, 'Name 1')

• Lookup(2, 'Name 2')

• {1, 'Name 1'}

• {2, 'Name 2}

• [1, 'Name 1']

• [2, 'Name 2]

Predifined ref-property:
- index (0..)
- number (1..)
- position (1..)

Maybe need special PropertyProvider for the control
See 'displayProperty', when we use this property we use PropertyProvider?

[Oleh Hapon]

Implemented for ComboBox and ListBox only (ref-property='number').
Need implementation for any property of Item.
Maybe need special PropertyProvider for the control.