Keep Illegal Blocks

1. Overview

• Updated the restoration system to support connectable blocks, preventing unwanted block updates for glass-panes, walls and fences (fences, iron bars and copper bars).
• Fixed blacklisted fragile blocks items not being dropped when they are broken (only blacklisted ones, not blocks being broken due to getting over the max-blocks limit).
• Added redstone-wires as fragile blocks.
• Removed support for CHORUS_FLOWER as fragile blocks because their restoration doesn't work properly. Note that CHORUS_PLANT is still supported.
• Completely reworked material loading process on server start (or plugin reload), to improve performance and allow non-block materials to be loaded (such as redstone-wires).
• Split and heavily refactored the main configuration class.
• Updated the PacketEvents optional dependency to 2.12.1+spigot.

2. Connectable blocks

A connectable block is a block that automatically connects to its adjacent blocks. This includes the following categories:

• fences (fences, iron bars and copper bars)
• glass-panes
• walls

Connectable blocks behave in a similar way to fragile blocks:

• Their connections can be modified illegally with a Debug Stick, or plugins like Axiom or WorldEdit.
• A connectable block will revert to its normal state when a physics update is triggered on one of its adjacent blocks.

This is why the restoration system has been made compatible with connectable blocks.

Connectable block updates are removed from network packets when they are restored (if the PacketEvents plugin is present). However, in most cases, they are still rendered by the client before the related network packet is received, which causes flickering for a fraction of a second.