mon/MonitorDBStore: uninline init_options

These assume leveldb but we can't reference that from the header
(for ceph-dencoder's sake).  Not that this is firefly-only; upstream
this has been cleaned up.

Signed-off-by: Sage Weil <sage@redhat.com>
mon/MonitorDBStore: use generic KeyValueDB::create()

Signed-off-by: Sage Weil <sage@inktank.com>
(cherry picked from commit a2a36192c28e4961b92c576172185a915daef366)
configure.ac: allow --with-server=false

Signed-off-by: Sage Weil <sage@redhat.com>
Makefile: make most stuff conditional on ENABLE_SERVER

Signed-off-by: Boris Ranto <branto@redhat.com>
configure.ac: only require leveldb if ENABLE_SERVER

Signed-off-by: Sage Weil <sage@redhat.com>