misc: formatting fixes
dnet: fix DNET_FLAGS_DIRECT flag behavior

Prevously DNET_FLAGS_DIRECT only affected node until route table update
or check timeout. This commit adds direct_id to session structure and corresponding methods
set_direct_id and get_direct_id for it's manipulation. If direct_id is
set then all requests always routed to the node which is responsible for
direct_id.id range.

NB! This change breaks ABI.
recovery: merge: rollback workarounds
recovery: remove lru_cache from node and session