add fields for Identify and ListSets

[nicolasfranck]

Changed:

• adminEmail is repeatable (can be string or array of string)
• add fields compression and description to Identify. Both are optional, and both can be string or array of strings. Module does not try to validate de XML data in 'description', so it can be wrong.
• add field setDescription to ListSets. Can be string of array of strings. Also here, I try not to validate the xml.