[ajax] refactor/cleanup low-level ajax functions
* loadxhtml/replacePageChunck/reload_component/reload_box deprecated in favor of loadXHTML / ajaxFuncArgs
* some other cleanups in cubicweb.ajax.js
* add js_render which will replace js_component (more generic, nicer argument passing handling)
# some entities have been added before schema entities, fix the 'is' and
# 'is_instance_of' relations
for rtype in ('is', 'is_instance_of'):
sql('INSERT INTO %s_relation '
'SELECT X.eid, ET.cw_eid FROM entities as X, cw_CWEType as ET '
'WHERE X.type=ET.cw_name AND NOT EXISTS('
' SELECT 1 from is_relation '
' WHERE eid_from=X.eid AND eid_to=ET.cw_eid)' % rtype)