Remove the disliked *_from calls from the objdb and recast

Remove the disliked *_from calls from the objdb and recast
the confdb library to use the new find_create/find_next/find_destroy API
calls instead.

I've kept the libcondfb API the same as before with the single change of
adding a confdb_object_find_destroy to tidy up the find handle after
use. If you don't call this then libcondfb will do it for you when
confdb_finalize is called.

git-svn-id: http://svn.fedorahosted.org/svn/corosync/trunk@1660 fd59a12c-fef9-0310-b244-a6a79926bd2f