updating object expirer to generate config

Now one should be able to generate the object-expirer.conf using
the default attributes (which are 1.8.0 compatible) and also include
more attributes (related to 1.9+) by including it on the swift environment
Merge branch 'object_exp_updates' of github.com:btorch/swift-private-cloud into object_exp_updates

Conflicts:
	recipes/admin-server-object-expirer.rb