Profile performance of store reads

[NiloCK]

message.From = *e.store.GetAddress()

Implementation dependant, but I believe current buntdb implementation does a read from disk on each lookup like this. This function is part of delivering a voucher, so could be called frequently. I don't know how a disk read compares against applying a signature in terms of OPS/second.

Data like the client (node) address (non security related, frequently referenced) might instead want to be made a top level in-memory member of the client loaded once at construction time.