Added: Option to toggle ProtocolLib usage
Updated: Ignore dependency-reduced-poms
Updated: Fixed typo
Updated: Print exception class if can't register command
Fixed: Creative mode will no longer wipe SpawnInfo (thanks to @aadnk)

This commit is a hefty one. Overall, it prevents creative mode from clearing SpawnInfo if an item is manipulated while in that mode. Added in this commit:
- ProGuard! This may be a huge issue for a while, as I discover what it's removing. It's a code optimizer (and obfuscater, but I'm not using that). It removes unused code and optimizes the underlying bytecode in Java.
- To accommodate ProGuard, dependencies are copied during the package phase of Maven. They are deleted after ProGuard finishes its job.
- The original jar and pre-ProGuard jar are deleted during packaging, leaving only one jar file in the target folder.
- The reason ProGuard was needed: ItemRenamer is now shaded in. It is /not/ a dependency! It has the code necessary to fix creative mode, and I have shaded it into RoyalCommands. If you already have this plugin, it won't hurt your server; it's moved after shading into RoyalCommands' directory structure, and the unused code (most of the plugin) is removed with ProGuard.

A big, big thank you to @aadnk. Without him, this commit never would have happened. He graciously helped me for two or three days, staying up until sometimes five in the morning. He also allowed me to shade the whole ItemRenamer plugin into RoyalCommands, despite ProGuard removing most of it. He also made spawned item tagging possible by providing the AttributeStorage system, so he's doubly to thank!