- add selection buttons to getter and setter in
  SelfEncapsulateFieldInputPage.createControl and tie these buttons
  to the associated text field's enablement and content
- only create a getter or setter if the name is non-empty.
- if field is final the setter creation is dísabled

Change-Id: Iac514c387c240aa9f700d7603b1b3dd8f8cc5232
Signed-off-by: Kenneth <kenneth@kean.nu>