put this_node_id_ into the mutex lock
use shared_ptr to wrap COW string avoid data racing
NodeId forced copy (avoiding raw_id_ becoming invalid after movable constructor being called)
avoid the situation when empty connection_ptr is returned
capture by value
Merge pull request #51 from maqi/MAID-545_LNC_thread_sanitizer

Maid-545_LNC_thread_sanitizer
Merge branch 'next' into account_transfer
Merge branch 'next' into account_transfer
Merge remote-tracking branch 'origin/next' into routing_v2

Conflicts:
	src/maidsafe/rudp/connection.cc
	src/maidsafe/rudp/connection_manager.cc
	src/maidsafe/rudp/managed_connections.cc