Disable annotations on pages in xwiki/1.0 syntax

Annotations feature backend relies on the new rendering engine, which is why, for pages in xwiki 1.0 syntax, it will use the converter before rendering the annotations. Since the converter is not perfect for some pages with complex scripting, it can cause problems (among which crashing the wiki was observed, by provoking an infinite loop – more investigation is needed in this direction though).

Also, all the pages in the default .xar are in syntax xwiki/2.0 and all the new documents are created in xwiki 2.0 syntax by default, so disabling annotations on xwiki/1.0 syntax should not affect a default, clean wiki.