to reduce the memory footprint when linking ceph-dencoder.
* src/tools/ceph-dencoder:
* build dencoders as shared libraries named with the prefix of
"den-mod-". so ceph-dencoder can find them
* install dencoders into $prefix/lib/ceph/denc, so ceph-dencoder
can find them
* only expose "register_dencoders()" function from plugins.
* load plugins in specified directory
* ceph.spec.in: package plugins
* debian: package plugins
Signed-off-by: Kefu Chai <kchai@redhat.com>
