Added ability to make custom signs/holograms through the PlaceholderAPI.

Two placeholder variables exist in the format of:

• %bomberman_info_<game>_<stat>%
  • <game> is name of game
  • <stat> is any of the localization parameters
• %bomberman_msg_<msg>%
  • <msg> is a custom localization message
  • The message has two variables passed into it:
    • {games}: a list of all active games
    • {player}: the PlaceholderAPI reference player (if existing)

Example placeholder usage:

• %bomberman_info_mygame_players%/%bomberman_info_mygame_spawns%
• %bomberman_msg_{games|get|mygame|{!it|players}/{!it|spawns}}%

Breaking changes:

• How message formatting works on lists has changed

Additional changes

• Added {#rand} format
• Added {!..} syntax for delayed expansion
• Added 'get' to list format
• Added 'filter' to list format