bundle2: move all parts into a `bx2` namespace
All currently core parts are moved to a `bx2` namespace (for "bundle 2
experimental"). This should avoid conflicts between the final stable
format and the one about to be released.
<table class="slogEntry parity{parity}">
<tr>
<td class="age">{date|rfc822date}</td>
<td class="author">{author|person}</td>
<td class="node"><a href="{url|urlescape}rev/{node|short}{sessionvars%urlparameter}">{desc|strip|firstline|escape|nonempty}</a></td>
</tr>
</table>