trim DataManager account
removing subscribes_ and passing compilation
WIP

Conflicts:
	src/maidsafe/vault/data_manager/service.h
	src/maidsafe/vault/operation_handlers.cc
	src/maidsafe/vault/operation_handlers.h
pass maidsafe_vault compilation

Conflicts:
	cmake/data_manager.message_types.meta
no need to MarkNodeUp anymore
DataManager acting when notice a connected node is down
DataManagerValue only contains pmids, no differentiate of online and offline
prune storage nodes when reached cap
remove action_node_down and action_node_up
remove IncrementSubscribers,DecrementSubscribers,SetPmidOnline,SetPmidOffline
complete removing of SetPmidOnline / SetPmidOffline (missed during git rebase)
DataManager send out chunk_size
comment out outdated DataManagerTests
remove MetaData in DataManager
DataManager only use its private database accessor
Merge branch 'account_transfer' into MAID-315_Update_DataManager_account_rebase
change chunk_size to uint64
minor corrections
more explicitly naming
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