[Ohrrpgce] SVN: teeemcee/13246 sliceedit: replace sliceed_rule_byte with sliceed_rule_ubyte

[subversion at HamsterRepublic.com]

teeemcee
2023-04-25 19:41:58 -0700 (Tue, 25 Apr 2023)
264
sliceedit: replace sliceed_rule_byte with sliceed_rule_ubyte

Changed all the 8-bit-enum types used in Slice into ubytes instead of bytes.
I left sliceed_rule_byte commented, we'll likely use it in future.

sliceed_rule_ubyte is useful for 0-255 colour components.
---
U   wip/sliceedit.bas
U   wip/slices.bas
U   wip/slices.bi
U   wip/util.bas
U   wip/util.bi