[table view] some new table view enhancements
* rewrite entiy table view column renderers to use default_* methods instead
of lambda so that column_renderers may be properly deep-copied
* new RelatedEntitiesColRenderer
* default addcount to false on RelatedEntityColRenderer
* more doc
debian/tmp/usr/lib/PY_VERSION/site-packages/cubicweb/web usr/lib/PY_VERSION/site-packages/cubicweb
debian/tmp/usr/share/cubicweb/cubes/shared/data usr/share/cubicweb/cubes/shared
debian/tmp/usr/share/cubicweb/cubes/shared/wdoc usr/share/cubicweb/cubes/shared