Fixed default namespace not being added when wrapping block categories by their ids [PS-131]
Additions:
Added an option to opt-out of MvDWPlaceholderAPI to skip the placeholder injection. This setting is enabled by default, however, you can simply disable it if you don't use PlotSquared placeholder with FeatherBoard or don't want to use FeatherBoard's build in placeholders and simply use it with PlaceholderAPI, that works as well.
Added a debug (/plot toggle debug) onto onBlockIgnite event notifying players to set the block-ignition flag when using flint and steel before cancelling the event.
Added a debug (/plot toggle debug) onto onEntityBlockForm event notifying players if the ice-form flag is not set before cancelling the event.
Don't send notify-enter/leave messages if vanished players visit a plot. [PS-103]