updated version preparing for new release
added link to registration form
put back to 0.21-snapshot until some newly discovered issues are fixed
updated to released version of poi 3.9, with rightfield patch applied
fix to handle csv export for spreadsheets that contain numeric (or other non string) content
fix to InvalidArgumentException when trying to read validation from a workbook containing macros - caused by an empty formula which then fails to create a constraint. Thanks to Jacob Rousseau for contributing assistence with this issue
Fixed tests related to loading MGED ontologies

error seems to be caused by a change to a remote ontology rather than
RightField code as the error also occurs when rolling back to earlier
versions.