Targeted dialogue for playing against X players with tag Y.

Adds two features to targeted dialogue:

1. If you have multiple targeted cases that fit the current criteria, rather than always picking the first target alphabetically, it will pick one at random. In other words, if you have three alsoPlaying cases and you're playing against all three of those opponents, it will use lines from all of them instead of the same one all the time.
2. Tag counters. For example, <case tag="must_strip"><condition filter="x" count="3" /><state>...</state></case> will apply if 3 players have the tag "x". For a practical example, <condition filter="rwby" count="4" /> will apply if all 4 RWBY characters are in the game.