Currently, standalone page-server can only receive pages from the remote
dump. Extend it with the ability to serve local memory dump to a remote
lazy-pages daemon.

travis-ci: success for lazy-pages: improve testability (rev2)
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>