Update:
This the final form that I am going to commit: an AMD module called
"xwiki-meta" that you can use this way:
require(['xwiki-meta'], function(xm) {
  xm['document'];
  xm['wiki'];
  xm['space'];
  xm['page'];
  xm['version'];
  xm['restURL'];
  xm['form_token'];
}
In consequence, javascript.vm will be modified this way:
require.config({
  paths: {
    // ...
    'xwiki-meta':
'$stringtool.removeEnd($xwiki.getSkinFile('js/xwiki/meta.js'),
'.js')'
   // ...
  },
 // ...
});
If you have any objection, please answer before the release of 6.3
Milestone 2 (on monday).
Thanks,
Guillaume