grep: fix wrong rlcass splitting (thanks erik and kenji)

add 0xffff to tab1 as range 0xffff-0x10ffff has 4 byte utf-8 sequence.
use Runemax (0x10ffff) instead of Runemask (0x1fffff) to denote
the last valid rune for inverted [^] match as Runemask is out of the
valid rune space.
grep: fix tab2, use int instead of Rune to be compatible to 16bit rune system
games/gb: better video scaler from games/nes
merge
sam, acme: fix character classes quoting for 21-bit runes

quote handling was broken with 21-bit runes. nextrec()
returned quoted rune as long rune | (Runemax+1) to escape
it.

with 16-bit runes, storing that long into 16-bit Rune
would automatically remove the escaping, but with 21-bit
runes, Rune is uint32 so the escaping would remain. we
now use (Runemask+1) instead, and mask the escaping off
explicitely when storing back to Rune.