Bugs found in mei21To30.xls

[Jonasmortensen]

Here follows some issues where a 2.1 MEI file is transformed incorrectly:

• <annot> elements inside <notesStmt> are not copied correctly if they contain a <p> element.
  If an <annot> element is empty, it is copied over even though it is not allowed to be empty.
• The <acqsource> element which is not allowed any more is not removed.
• Contents of an <expression> element is only copied over if it contains a <history> element. I should be copied either way.
• All elements in an <event> are surrounded with a <label> containing the text of an old <p> element. The <p> should instead just be renamed to <desc> and placed the same way. Meaning no surrounding <label>.
  This is when using the data-like organization.
• The <biblList> element of an event is not copied over.