Updated db commit to return deleted value.
Initial work on Vault Delete operation
Initial work on Vault Delete Operation
Modified db::comit() and updated actions in sync.
Minor work on Vault
Merge remote-tracking branch 'origin/next' into get_implementation

Conflicts:
	src/maidsafe/vault/data_manager/service.cc
	src/maidsafe/vault/data_manager/service.h
	src/maidsafe/vault/maid_manager/service.h
	src/maidsafe/vault/operations_visitor.h