[forms] remove dead code and simplify inlineviews creation remove AutomaticEntityForm.should_inline_relation_form which is not used anywhere and comes from a time where uicfg did not exist. remove test for "force_<rtype>_display" presence in req.form to determine whether or not the inline creation form should be displayed.

function set_tab(tabname, cookiename) {
    // set appropriate cookie
    loadRemote('json', ajaxFuncArgs('set_cookie', null, cookiename, tabname));
    // trigger show + tabname event
    trigger_load(tabname);
}