embedded: Add RADOS classes to embedded cephd library

embedded: Add RADOS classes to embedded cephd library

RADOS classes can now be statically compiled and added to
the embedded cephd library.

The RADOS ClassHandler now has an option to skip calling dlclose
just like PluginRegistry.

All RADOS classes where changed to use a CLS_INIT macro that
will either use __cls_init or classname_cls_init. this enables
the static compiling of all RADOS classes in a single library. Also
global method definitions where moved to inside cls_init.

Also added a few aconfig defines including WITH_EMBEDDED, WITH_CEPHFS,
WITH_RBD, and WITH_KVS. Note that WITH_RBD was not defined before
and the ceph-dencoder was broken when it was turned on.

Signed-off-by: Bassam Tabbara <bassam.tabbara@quantum.com>