add gem 'representable'
representer use in imprint
use decorator instead of extend
add gem 'virtus'
overwrite to_xml and from_xml of imprint and virtus use instead of roxml
revert spec to original state
Merge branch 'origin/master' into virtus_and_representable
revert delete gem 'roxml'
use Proc in :getter
Update sender_identifier
fixes in addressee_identifier
add xml file example and given spec
Update addressee_identifier
Update product_identifier
Update series_identifier
Add specs for access to series IDs
Update series
Allow using a generic render filter for representer properties
Using render_filter instead of getter
Update title