Multiple block read fails with error 127 or 63.

[Anton-2]

readblocks with multiple block fails when using fast/new cards.
The card returns a non 0 status after CMD12 (end of transfert).
It may work with old/small/slow cards when ignoring some 127 returns.

I suspect it's because we are releasing CS between reads. Preliminary testing of a modified version that does not release CS shows fiable reads, and performance around 250KB/s on a pyportal (24Mhz SPI bus). I expect to provide a PR for this in a few days, after more testing/cleanup.

[Anton-2]

Fixed in #26