More Variables in Messages + Small Fixes.

[MrShadow-X]

• Added {vPrefix}, {vSuffix}, {player}, {owner} to all party messages that had {player} variable by default.
• Added {player}, {vPrefix}, {seconds} in "countdown shortened" message and changed /bw start debug countdown time to this from config.
• Fixed showing health message with "-" and showing it when player hits enemy with other projectiles than arrows.
• Fix Y-KILL-HEIGHT message. (When jumping into void it was returning message that I've died, not that I felt into the void.)

[ImYenil]

Caused by: java.lang.IllegalArgumentException: No enum constant org.bukkit.event.entity.EntityDamageEvent.DamageCause.FLY_INTO_WALL