This improves policy logs. @gmaxwell was complaining about “ERROR: AcceptToMemoryPool: nonstandard transaction: dust” the other day, so I think he will be happy to have it replaced with “Rejected by local policy: AcceptToMemoryPool: IsStandardTx: dust”. Of course, the log strings and the newly created reject reasons are open for bike-shedding.
As usual, I would prefer to do this after #6068.