add image to redturtle portlet collection
Update HISTORY.txt
add translations
Update HISTORY.txt
Merge branch 'portletimage' of github.com:luca-bellenghi/redturtle.portlet.collection into portletimage
Merge pull request #3 from luca-bellenghi/portletimage

Add reference field to refer an image to show under the header; add some italian translation; fix rss icon on portlet header