added first memcached-replication test
1. Move test to memcached folder
2. Add expiration tests
3. Move tnt-memcache configs to cfg folder
1. Restructuring memcached/replication -> replication/memcached
2. Delete raw sleeps from replication-memcached test
3. Add check, that replica expires even when it becomes master
Fixes int replication/memcached test:
1. Not waiting for flush_all
2. Delete redundant time.sleep() and wait()'s
3. Fix for cfg files
Fix notes from CR of k.osipov:
1. sleep(0.1) -> sleep(0.01)
2. _server -> serv, _replica -> _repl.
Remove trailing space.