Fix running commands from console

Using Vault for permissions checks is stupid since Vault just uses Bukkit's player.hasPermission. Checking for OP is pointless, as OPs have all permissions.

Moved (sender instanceof player) checks to the couple commands that can only be run in-game.
Update DevCommand.java
Merge pull request #25 from BlackBeltPanda/v2.0.0

Fix commands executed from console