Content-Repository Reform: reduce dependency on cr_child_rels and make
creation of cr_child_rels entries optional. Most applications do not
need cr_child_rels, these take substantial space and slow down
operations. The change is fully backward compatible, since per
default cr_child_rels are still created. First tests show an
improvement for the creation of cr_items by 17% and for deletion by
28% (when parent item is a plain cr_item, as it is e.g. the case in
xwowiki). Same change made as well for Oracle.
- affected functions (here with pg-names)
* procedure content_item__new/21 (version for text or file entries) has new optional boolean parameter: with_child_rels
* procedure content_item__new/17 (version for blob entries) has new optional boolean parameter: with_child_rels
- remove/reduce dependency on cr_child_rels (if no rel-tag is used, the chile-information is obtained from cr_items)
* content_item__is_publishable/1
* content_item__is_valid_child/3
* content_item__is_valid_child/2
- reduce number of functions by using defaults
* content_item__copy/5
* content_item__get_title/2
* content_item__move/3
