This commit adds a new per-arena setting, join-interrupt-timer, which, when set to a positive number, will introduce a delay to the join and spec commands. During this delay, if the player takes damage or moves more than one block's distance, the command will be interrupted.
Closes#482
This, along with a (currently not committed) script to generate github releases and Spigot/DBO formatted release notes from this changelog, should reduce some of the friction associated with new releases.
