2fb9c1e shuffle selected coins before transaction finalization (Gregory Sanders)
Pull request description:
Currently inputs are ordered based on COutPoint ordering, which while doesn't leak additional internal wallet state, likely further fingerprints the wallet as a Core wallet to observers.
Note: This slightly changed behavior of `fundrawtransaction` in that the newly-appended inputs will now be shuffled rather than in outpoint-order. This does not break API compatibility.
Simple shuffling of the coins being returned will hopefully allow the wallet to blend in a bit more, in lieu of additional data to find what other wallets are doing, or another standard, ala @gmaxwell's suggested of ordering via scriptPubKey.
Tree-SHA512: 70689a6eccf9fa7fc6e3d884f2eba4b482446a1e6128beff7a98f446d0c60f7966c5a6c55e9b0b3d73a9b539ce54889a26c7efe78ab7f34af386d5e4f3fa6df2