Added the following Placeholders (PlaceholderAPI)

• %dragons_unformatted_personal_time_MAP% - Returns the player's time from a map
• %dragons_personal_time_MAP% - Returns the player's formatted time (mm:ss.SSS) from a map

Added arena display names

• You can use this to use non-alphanumeric symbols and spaces for you arena.
• Your arena name is still valid and usable, but you'll be able to use the display-name for sign, commands and placeholders.
• You can set your arena display name by using /dragons setDisplayName <arena> <new display-name>

If the display name is missing or broken in some place let me know, they have to be manually replaced to not break the arena so I might have missed some.