- Before, some returned bool, and others returned int (which was then turned
into a bool with a comparison); now, everything returns a bool
- Before, some set hashes_done to nonce - 1 when a share was found and others
set it to nonce + 1 or 2. This caused some algorithms to scan/submit shares
twice with the new cpu_scanhash function. Now, it has all been replaced with
last_nonce, which is set to the final nonce checked by the scanhash_* func.
- VIA needs the full data, and cannot use midstate. All the others were
expecting midstate and data+64 for their parameters. Now, we pass midstate
and the full data pointer, and let the scanhash_* function choose which to
use.
Previously, we would stop the scan if the high 32 bits of the hash were zero,
as a quick shortcut for testing the full hash. If this quick test succeeded,
we would pass the work to the server for full validation.
Change this logic to perform full validation inside minerd, so that work may
be resumed more quickly if hash > target.
