Fixes our own, and upstream's, issues with the stricter Java 8 JavaDoc
linter.
Also removes the destroystokyo-release maven repository. I'm not sure
why I added it originally, but it's unnecessary now.
Spigot has patched this issue inside MapIcon, meaning that we no longer need to maintain this patch; Spigots patch also fixes#668 in that it will verify the length of the array, as well as protect against a negative type value being fetched from the array. Only real change is that Spigots patch returns a MapIcon.Type.PLAYER, instead of the RED_MARKER as originally PR'd by Aikar.
Also add "commands" to Tab Completion
Note: This required a signature change to Bukkit#reloadCommandAliases() so that it returns a boolean based on if the command aliases reloaded or not.
