Errors in examples

[infojunkie]

At infojunkie/musicxml-midi#40, I am working on extracting the MusicXML examples to use them as test cases.

Part of my script validates each example using xmllint and the 4.0 spec. I found that 5 examples are not validating:

• accordion-middle-element: Element 'accordion-middle': '' is not a valid value of the atomic type 'accordion-middle'.
• circular-arrow-element: Element 'circular-arrow': [facet 'enumeration'] The value 'anti-clockwise' is not an element of the set {'clockwise', 'anticlockwise'}.
• interchangeable-element: Element 'time-relation': This element is not expected. Expected is ( beats ).
• inversion-element: Element 'inversion': This element is not expected. Expected is ( kind ).
• voice-element: Element 'tuplet', attribute 'bracket': [facet 'enumeration'] The value 'none' is not an element of the set {'yes', 'no'}.

I'll be submitting a PR to fix these errors.

[mscuthbert]

Thanks -- these look right to me -- I'm going to set up a 4.1 branch and then merge.