* Warn the user that fields with no value and not it the field template list
  will be removed from the component before exiting the edit component in
  schematic dialog.
* Add a function to TEMPLATES class to check if template list contains a
  field with a given name.
* Move the function to display the edit component in schematic dialog into
  the SCH_EDIT_FRAME class.
* Doxygen and coding style policy fixes.