Critical bug fixes + Permissions improvement

[ + ] Fixed masks not working when sellhead cases were not being ignored.

[ + ] Fixed /sellhead acting in a similar fashion as above.

[ + ] Also fixed /sellhead (in general) printing an error when a transaction is complete; this is just in printing the error itself, you still received money even if the plugin stole all the heads from your inventory.

[ + ] Fixed some commands throwing errors if you have the tellraw option enabled.

[ + ] Fixed the debug reporter having an existential crisis; it will now print the original exception when it runs into an exception itself.

[ + ] Running /sellhead will no longer remove heads from your own head - this is useful if you're using heads as masks.

[ + ] Added subpermissions to /hp headinfo, /hp xp and /hp debug for extra security. I will be including these in the wiki following a brief break.

[ + ] Enhancing the plugin.yml and including descriptions for the majority of HP's permissions, still a work in progress but due to the urgency of this update, may not be finished in the final release.

This is currently a trial build.