Plugins can ship drawn dialogs

• New API: installDrawn(plugin, namespace) installs drawn dialogs a plugin carries in its jar, once per version of that plugin. Any the server owner has edited are kept as they are. Their resource pack is sent when one is first opened, never on join.
• New API: setting(player, name) reads what a drawn dialog's switch, slider or dropdown is set to for that player.
• Fixed: a button inside a list on a drawn dialog (a row of players, a row of history entries) did nothing when clicked.

0.3.5: A permission per command

Every /de command has its own permission now, so you can hand out just the ones you want.

• dialogengine.list, .open, .info, .edit, .pack and .reload, one per subcommand, plus dialogengine.open.others for opening a dialog on somebody else.
• dialogengine.admin still grants them all, so nothing changes for a server that uses it.
• The "players download the pack from..." hint, when a drawn dialog's pack fails to load, now goes to holders of dialogengine.pack.notify.
• /de lists only the commands you can use, and tab completion only offers those.