[ajax] use a custom tag to handle dynamically loaded js Using <pre class="script"> makes it trivial for a malicious user to inject arbitrary javascript into a html or rest text element (because it looks innocent to the html sanitizer). Using a custom tag we can be sure that it actually comes from our code and not from untrusted user data. IE ignores custom tags, though, so we put it in its own namespace. https://extranet.logilab.fr/1530578

if repo.system_source.dbdriver == 'postgres':
    sql('ALTER TABLE appears ADD COLUMN weight float')
    sql('UPDATE appears SET weight=1.0 ')