allow object overrides with CDIST_ALLOW_OVERRIDE=true
added some ideas from asteven and a bit more description about the order
in the manpage
forgot the : after the else ...
Merge branch 'feature_object_override' of git://github.com/dheule/cdist
examples are always the last section

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>
update override documentation

Signed-off-by: Nico Schottelius <nico@bento.schottelius.org>