Update to bsnes v107r4 beta release.

byuu says:

  - bsnes: added video filters from bsnes v082
  - bsnes: added ZSNES snow effect option when games paused or unloaded
    (no, I'm not joking)
  - bsnes: added 7-zip support (LZMA 19.00 SDK)

[Recent higan WIPs have also mentioned bsnes changes, although the higan code
no longer includes the bsnes code. These changes include:

  - higan, bsnes: added EXLOROM, EXLOROM-RAM, EXHIROM mappings
  - higan, bsnes: focus the viewport after leaving fullscreen exclusive
    mode
  - bsnes: re-added mightymo's cheat code database
  - bsnes: improved make install rules for the game and cheat code
    databases
  - bsnes: delayed construction of hiro::Window objects to properly show
    bsnes window icons

- Ed.]

nall/cd/crc16.hpp

@@ -0,0 +1,18 @@
+#pragma once
+
+//CRC-16/KERMIT
+
+namespace nall::CD {
+
+inline auto CRC16(array_view<uint8_t> data) -> uint16_t {
+  uint16_t crc = 0;
+  while(data) {
+    crc ^= *data++ << 8;
+    for(uint bit : range(8)) {
+      crc = crc << 1 ^ (crc & 0x8000 ? 0x1021 : 0);
+    }
+  }
+  return ~crc;
+}
+
+}