Specify what kind of OSM object has the Wikipedia tag

If an article is tagged, show the type of OSM object in the icon
that links to the OSM object web page.
Add to categories links to add-tags tool, from WIWOSM

If not all the articles of a category have Wikipedia tags, show
a link to the add-tags tool from WIWOSM

http://wiki.openstreetmap.org/wiki/JOSM/Plugins/RemoteControl/Add-tags

with the parameters: category name and country bbox
Improve info on homepage