update port: games/bzflag to version 2.0.0
Update games/bzflag port to version 2.0.0. It might be
useful to have some people test v2 long enough to confirm
that people prefer it to v1.x. If the users prefer, it
might be better to create a new port games/bzflag2, but I
will wait for feedback which indicates this.
Submitted by: Charles Swiger <email@example.com>