BibEdit: moving fields/subfields, stripping fields

• The order of fields can be changed now, the fields can be moved up or down with keyboard shortcut Ctrl-Up Ctrl-Down. Focus remains on field/subfield after moving for faster editing.

• Removed arrow buttons for moving subfields. Now the only way to move field/subfields is Ctrl-Up/Ctrl-Down.

• Fixed bug when adding new field, it was impossible to move it.

• Upon submission of the record, it is checked for empty fields or subfields, which are removed. Useful when submitting a record created from templates, and a field or subfield is not filled in by the inputter.

• Link to BibMerge activated in case the record was modified by others.