incorporate eml parser into Morpho
Currently, a full check of the eml created by Morpho is not done until a package
is submitted to metacat where the submission is rejected if the package is not
valid or does not meet other requirements defined in the eml2 parser.
It would be useful to have the eml parser incorporated in Morpho and have it
provide some more meaningful messages (e.g. "customUnit information in
'additonalMetadata' is missing or invalid")