Currently solely used for single signer change outputs, intended to be
used for funds into Serai and multisig change outputs (dependent on #2).
Also cleans the file layout, makes scanning a bit more robust, doesn't
return outputs of amount 0, and shuffles outputs.
Remove's CLSAG's msg Rc for the msg available through AlgorithmMachine.
Potentially slightly more inefficient, as it needs to be converted from
a slice to a [u8; 32], yet removes a re-impl.
Also removes a match for an if.
Updates decoy selection with an explicit panic, the removal of a divide
by 0 (causing tests to fail on new chains), and a minor optimization
when dealing with a large quantity of locked outputs.
Also increases documentation, acknowledging infinite loops and breakage
from Monero more.
While all the transcript/extension code works as expected, which means,
they don't cause any conflicts, n was still capped at u64::MAX at
creation when it needs to be u16. Furthermore, participant index and
scalars/points were little endian instead of big endian/curve dependent.
Updates CLSAG signing as needed. Moves around Error types.
CLSAG multisig and the multisig feature is currently completely borked
because of this. The created TXs are accepted by Monero nodes.