GitLab

Two changes in this commit:
- All meters now explicitly specify "maxItems" property, even for just
  1 item. (Exception is "container" CPU meter classes, which use
  CUSTOM_METERMODE.)
- "maxItems" being 0 is now allowed. This will let bar meters and graph
  meters render an empty meter.

See https://bugzilla.redhat.com/show_bug.cgi?id=987805 for details.
(thanks to Dawid Gajownik for the detailed analysis!)

Changes in object model: separate class objects to store vtable. Also, nicer UTF-8 display of big numbers.