Alias cue_ball -> billiard_ball and imply billiard_ball -> ball

BUR #7055 has been approved by @nonamethanks.

create alias cue_ball -> billiard_ball
create implication billiard_ball -> ball

Ball is used as an umbrella tag, other types of ball already implicate it.

Since we're in topic, this should really be called billiard ball. Apparently cue ball only describes the white one.

nonamethanks said:

Since we're in topic, this should really be called billiard ball. Apparently cue ball only describes the white one.

Right. I edited the BUR accordingly.

The bulk update request #7055 (forum #195913) has been approved by @nonamethanks.